Abstract:
A composition for forming metal objects includes (a) first particles containing a jewelry-metal, and (b) second particles containing a refractory metal oxide. The composition allows the preparation of jewelry-metal in a large variety of colors.

Description:
BACKGROUND 
     The present invention relates to metal clays with refractory stains. 
     Upon sintering, jewelry-metal clays form pure or almost pure jewelry-metal objects that retain the basic shape of the jewelry-metal clay. The clays contain a jewelry-metal powder and a binder; the binder is mostly removed during the sintering process. Jewelry-metal clays are described in U.S. Pat. Nos. 5,376,328 and 5,328,775. Jewelry-metal clay is referred to in the trade as precious metal clay, or PMC, and is available from RIO GRANDE, 7500 Bluewater Road N.W., Albuquerque, N.Mex., 87121, among others. 
     The ability to color jewelry-metal objects is limited. Jewelry-metal gold is an excellent example. Although white, rose, green, and varying shades of yellow gold are known, each is made by alloying pure gold with a second metal. The achievable color variation in any jewelry-metal, whether 24 karat gold, 18 karat gold, 14 karat gold, 10 karat gold, Nu-gold (88% wt. Cu 12% wt. Zn), fine silver, sterling silver (92.5% wt. Ag/7.5% wt. Cu), nickel silver (65% wt. Cu/18% wt. Ni/17% wt. Zn), platinum, palladium, ruthenium, rhodium, aluminum, brass, lead, nickel, iridium, indium, copper, zinc, or combinations thereof, is typically limited to the alloys these metals form. Accordingly, there is a need to expand the varieties of colors of jewelry-metal articles. 
     Refractory stains have many uses and are widely used to color ceramics. Prior to firing, the stain is incorporated into the slip and/or applied as a glaze. The stains are prepared by mixing together metal oxides and various inorganic and metal binders, which are fired for color stability, and then ground. 
     BRIEF SUMMARY 
     In a first aspect, the present invention includes a composition for forming metal objects, including first particles containing a jewelry-metal, and second particles including a refractory metal oxide; The composition may be made by mixing these ingredients together. 
     In a second aspect, the present invention includes a metal object, containing a jewelry-metal; and second particles containing a refractory metal oxide, in the jewelry-metal. 
    
    
     DETAILED DESCRIPTION 
     Jewelry-metal clays and refractory stains may be combined to form a colored metal clay. When sintered, the colored metal clay forms a colored jewelry-metal article, due to incorporation of the stain. Because jewelry-metal clays are sintered to remove their binder constituents at temperatures lower than those at which refractory stains degrade, jewelry-metals having the color of the stain are possible. The stain is present on the surface and in the subsurface of the finished jewelry-metal article, not simply as a surface coating. The actual color of the final product will be influenced by the natural color of the jewelry-metal and the color of the stain. 
     Jewelry-metal clays form almost pure jewelry-metal articles after. sintering, preferably at temperatures of from 1470° F. to 1830° F. Because refractory stains do not undergo significant chemical reaction and degradation during sintering at these, and higher temperatures, the stains may be incorporated into the jewelry-metal clays. In the case of jewelry-metals which cannot tolerate sintering in air without significant oxidation, sintering may be carried out under vacuum, under an inert atmosphere, such as argon or nitrogen, or under a reducing atmosphere, such as hydrogen or methane. 
     Although the coloring of jewelry-metal objects is preferably achieved by mixing a refractory stain into a jewelry-metal clay before sintering, clays are not required. A jewelry-metal may be colored with stain, for example, by mixing the powdered metal and stain together, and then sintering the mixture below the melting point of the metal. Furthermore, once formed by any method, colored jewelry-metal may be mechanically formed into the desired shape using hand-tools, machines, or dies. Colored jewelry-metal wires could be produced in this manner. 
     As described in U.S. Pat. Nos. 5,328,775 and 5,376,328, a pure or almost pure jewelry-metal object may be formed as the solid-phase sintered product of a jewelry-metal clay. To manufacture the jewelry-metal article, a moldable clay mixture, containing a jewelry-metal powder and a binder, is shaped into a molded object. The molded object is then sintered. An almost pure jewelry-metal article results which retains the shape of the clay, typically with some shrinkage. To prevent the metal from melting and loosing the shape into which the clay was molded, the clay is sintered at a lower temperature than the melting point of the jewelry-metal. Sintering is defined as heating sufficiently to cause the metal particles to stick together, but below the melting point of the metal. 
     Moldable clay mixtures are produced by blending jewelry-metal powders with a binder. Preferably, the binder is a cellulose binder prepared by blending a cellulose with water. Addition of a surface-active agent during mixing of the jewelry-metal powder and binder allows for more uniform mixing in a short time period. Addition of an adhesion-preventing agent, such as di-n-butyl phthalate or an oil such as a vegetable oil, prevents the clay from sticking to the skin of the hand during molding. 
     A preferable moldable clay mixture contains 50 to 90% by weight of jewelry-metal powder with an average particle diameter of at most 1000 μm, preferably at most 600 μm, most preferably at most 200 μm; 0.8 to 8% by weight of binder, more preferably a water-soluble cellulose binder; 0.08 to 3% by weight of a surface-active agent; and 0.1 to 4% by weight of oil; with the balance water and unavoidable impurities. Sintering of this jewelry-metal clay results in a solid-phase sintered product of a jewelry-metal. 
     Currently, three jewelry-metal clays are available from RIO GRANDE. An 80% pure silver clay (STANDARD SILVER PMC) is available with a recommended sintering time of two hours at 1650° F. A 90% pure silver clay (SILVER PMC+) is available with a recommended sintering time of thirty minutes at 1470° F. This clay provides the benefits of less shrinkage, lower sintering temp, and less sintering time. A 24 karat yellow gold clay (STANDARD GOLD PMC) is also available with a recommended sintering time of two hours at 1830° F. Other jewelry-metal clays may be prepared by mixing powder of one or more metals or alloys with a binder, optionally a solvent which will evaporate or burn away (water, ethanol, isopropanol, methanol, acetone, etc.), optionally a surface-active agent, and optionally an adhesion-preventing agent (di-n-butyl phthalate, vegetable oil, etc.). 
     Jewelry-metal clays may also be formed by more conventional methods involving the combination of jewelry-metal powders and binders such as bentonite, clay, glue, and boiled rice or wheat flower, and optionally water, as described in Japanese Patent Applications laid open with Publication Numbers 59-143001 and 63-403. Unlike cellulose-binder clays, these binders may remain in the jewelry-metal article after drying or sintering. 
     Refractory stains have been used to color ceramic articles for over 100 years and are available in numerous colors. In addition to shades of pink, blue, black, white, crimson, coral, purple, orange, gray, green, brown, yellow, and red, many color shades are available; Refractory stains may be obtained as MASON STAINS, available from MASON COLOR WORKS, INC., East Second Street P.O. Box 76, East Liverpool, Ohio, 43920, or as WALKER STAINS, available from WALKER CERAMICS, 55 Lusher Road., Croydon, Australia, 3136. 
     Refractory stains are metal oxides which are fired for color stability to form refractory metal oxides and ground into a fine powder with an average particle diameter of at most 50 mesh (for example 254 to 297 microns), preferably at most 100 mesh (for example 122 to 149 microns), and most preferably at most 200 mesh (for example 50 to 74 microns). One or more oxides of metals such as aluminum (Al 2 O 3 ), antimony (Sb 2 O 3 ), boron (B 2 O 3 ), calcium (CaO), chromium (Cr 2 O 3 ), cobalt (CoO), iron (Fe 2 O 3 ), manganese (MnO 2 ), nickel (NiO), praseodymium (Pr 6 O 11 ), selenium (SeO 2 ), silicon (SiO 2 ), tin (SnO 2 ), titanium (TiO 2 ), vanadium (V 2 O 5 ), zinc (ZnO), and zirconium (ZrO 2 ) are combined in various proportions and then fired, to attain the desired color. In addition to metal oxides, refractory stains optionally contain various metal and inorganic binders. Any combination may be used, as long as the metal oxide stain can withstand firing at a temperature high enough to allow sintering of the metal clay. 
     The stains may be any color, including black, white, or transparent. To achieve greater color variation, mixtures of stains are possible, Some examples of the available stain colors and the metal oxide components combined to form them are provided in the following MASON COLOR charts. 
     
       
         
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 MASON COLOR COMPOSITION CHARTS 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 New 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 No. 
                 Greens 
                 Al 
                 Ca 
                 Co 
                 Cr 
                 Fe 
                 Ni 
                 Pr 
                 Si 
                 Sn 
                 Ti 
                 V 
                 Zn 
                 Zr 
                 See Ref. 
               
               
                   
               
               
                 6200 
                 Evergreen 
                   
                   
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                   
                 3, 5 
               
               
                 6201 
                 Celadon 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                 1, 3, 6, 8 
               
               
                 6202 
                 Florentine 
                   
                   
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                   
                 1, 3, 6, 8 
               
               
                 6204 
                 Victoria Green 
                   
                 X 
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 5, 9 
               
               
                 6206 
                 Grass Green 
                   
                 X 
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 5, 9 
               
               
                 6207 
                 Celeste 
                   
                   
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6209 
                 Chrome Green 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                   
                 3, 5 
               
               
                 6211 
                 Pea Green 
                   
                   
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                 X 
                   
                 X 
                 1, 3, 6, 8 
               
               
                 6219 
                 French 
                   
                 X 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                 1, 3, 5, 8 
               
               
                 6221 
                 Turquoise 
                   
                 X 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                 X 
                 3, 5 
               
               
                 6223 
                 Ivy 
                 X 
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                   
                 3, 5 
               
               
                 6224 
                 Dk. Green 
                   
                   
                 X 
                 X 
                 X 
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                 3, 5 
               
               
                 6226 
                 Dk. Leaf 
                   
                   
                 X 
                 X 
                 X 
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                 1, 3, 6, 8 
               
               
                 6234 
                 Myrtle Green 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 1, 3, 6, 8 
               
               
                 6236 
                 Chartreuse 
                   
                   
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                 X 
                   
                 X 
                 1, 3, 6 
               
               
                 6242 
                 Bermuda 
                   
                   
                   
                   
                   
                   
                 X 
                 X 
                   
                   
                 X 
                   
                 X 
                 3, 6 
               
               
                 6244 
                 Deep Sea 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                 1, 3, 6, 8 
               
               
                 6246 
                 Blue Green 
                   
                   
                 X 
                 X 
                   
                   
                   
                 X 
                 X 
                   
                   
                 X 
                   
                 3, 6, 8 
               
               
                 6254 
                 Dk. Teal Green 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                 1, 3, 6, 8 
               
               
                 6255 
                 Jade Green 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                 1, 3, 6, 8 
               
               
                 6263 
                 Victoria 
                   
                 X 
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 5, 9 
               
               
                 6264 
                 Victoria 
                   
                 X 
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 5, 9 
               
               
                 6265 
                 Leaf Green 
                   
                 X 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                 X 
                 3, 5, 9 
               
               
                 6266 
                 Peacock 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 1, 3, 6, 8 
               
               
                 6267 
                 Emerald 
                   
                 X 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 5, 9 
               
               
                 6268 
                 Sea Green 
                   
                   
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                 1, 3, 6, 8 
               
               
                 6271 
                 Mint 
                   
                 X 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                 X 
                 3, 5, 9 
               
               
                 6274 
                 Nickel Silicate 
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                   
                   
                   
                 1, 3 
               
               
                 6280 
                 Avocado 
                 X 
                   
                 X 
                 X 
                 X 
                   
                   
                 X 
                   
                 X 
                 X 
                 X 
                 X 
                 3, 6 
               
               
                 6288 
                 Turquoise 
                   
                 X 
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                 X 
                   
                 X 
                 3, 5, 9 
               
               
                 6296 
                 Dk. Spruce 
                   
                 X 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                   
                 1, 3, 6, 8 
               
               
                   
               
             
          
           
               
                 New 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 No. 
                 Blacks 
                 Co 
                 Cr 
                 Fe 
                 Mn 
                 Ni 
                 Sn 
                 Zn 
                 See Ref. 
               
               
                   
               
               
                 6600 
                 Best Black 
                 X 
                 X 
                 X 
                   
                 X 
                   
                   
                 1, 3, 6 
               
               
                 6601 
                 Velvet Black 
                 X 
                 X 
                 X 
                   
                 X 
                   
                 X 
                 1, 3, 6 
               
               
                 6609 
                 Black 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                   
                 1, 3, 6 
               
               
                 6612 
                 Onyx Black 
                 X 
                 X 
                 X 
                   
                 X 
                   
                   
                 1, 3, 6 
               
               
                 6616 
                 Chrome-Free 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                 1, 3, 6 
               
               
                 6650 
                 Cobalt-Free 
                   
                 X 
                 X 
                   
                   
                   
                   
                 3, 5 
               
               
                 6657 
                 Black 
                 X 
                 X 
                 X 
                   
                   
                   
                   
                 3, 5 
               
               
                 6666 
                 Cobalt-Free 
                   
                 X 
                 X 
                 X 
                   
                   
                   
                 3, 5 
               
               
                   
               
             
          
           
               
                 New 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 No. 
                 Blues 
                 Al 
                 Co 
                 Cr 
                 Fe 
                 Ni 
                 Si 
                 Sn 
                 V 
                 Zn 
                 Zr 
                 See Ref. 
               
               
                   
               
               
                 6300 
                 Mazerine 
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6302 
                 Cadet 
                 X 
                 X 
                 X 
                   
                   
                 X 
                 X 
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6305 
                 Teal 
                 X 
                 X 
                 X 
                   
                   
                 X 
                   
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6306 
                 Vivid Blue 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6307 
                 Pastel Blue 
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                   
                 X 
                 1, 3, 6 
               
               
                 6308 
                 Delphinium 
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                   
                   
                 1, 3, 6 
               
               
                 6310 
                 Wedgwood 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                 1, 3, 6 
               
               
                 6313 
                 Medium Blue 
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6315 
                 Zirconium Vanadium 
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 X 
                 1, 3, 6 
               
               
                 6320 
                 Delft 
                 X 
                 X 
                   
                   
                   
                 X 
                 X 
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6330 
                 Cobalt Aluminate 
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                   
                   
                 1, 3, 6 
               
               
                 6336 
                 Peacock 
                 X 
                 X 
                 X 
                   
                   
                 X 
                 X 
                   
                 X 
                   
                 3, 6 
               
               
                 6338 
                 Cobalt Meta-Silicate 
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                 1, 3, 6 
               
               
                 6339 
                 Royal 
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6343 
                 Mediterranean 
                 X 
                 X 
                 X 
                   
                   
                 X 
                   
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6350 
                 Bright Blue 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                 X 
                 X 
                 X 
                 1, 3, 6 
               
               
                 6360 
                 Willow 
                 X 
                 X 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                 3, 5 
               
               
                 6363 
                 Sky Blue 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                 1, 3, 6 
               
               
                 6364 
                 Turquoise 
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 X 
                 1, 3, 6 
               
               
                 6368 
                 Copen Blue 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6371 
                 Dark Teal 
                 X 
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                   
                 1, 3, 6 
               
               
                 6373 
                 Turquoise 
                   
                 X 
                 X 
                   
                   
                   
                 X 
                 X 
                   
                 X 
                 3, 6 
               
               
                 6374 
                 Dk. Turquoise 
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 X 
                 1, 3, 6 
               
               
                 6376 
                 Robin&#39;s Egg 
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 X 
                 1, 3, 6 
               
               
                 6378 
                 Zirconium Vanadium 
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 X 
                 1, 3, 6 
               
               
                 6383 
                 Cobalt Aluminate 
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                   
                   
                 1, 3, 6 
               
               
                 6386 
                 Navy Blue 
                   
                 X 
                 X 
                 X 
                 X 
                 X 
                   
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6388 
                 Mazerine 
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                 1, 3, 6 
               
               
                 6389 
                 Sapphire Blue 
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                   
                   
                 1, 3, 6 
               
               
                 6391 
                 Zirconium Vanadium 
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 X 
                 1, 3, 6 
               
               
                 6393 
                 Turquoise 
                 X 
                 X 
                   
                   
                   
                 X 
                 X 
                 X 
                   
                 X 
                 3, 6 
               
               
                 6396 
                 Peacock 
                 X 
                 X 
                 X 
                   
                   
                 X 
                   
                 X 
                   
                 X 
                 1, 3, 6 
               
               
                 6398 
                 Deep Peacock 
                 X 
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                   
                 1, 3, 6 
               
               
                   
               
             
          
           
               
                 New 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 No. 
                 Whites 
                 Al 
                 B 
                 Ca 
                 Si 
                 Sn 
                 Zr 
                 See Ref. 
               
               
                   
               
               
                 6700 
                 White 
                 X 
                   
                   
                 X 
                   
                 X 
                 3, 6 
               
               
                 6768 
                 Tin White 
                 X 
                   
                   
                 X 
                 X 
                   
                 3, 6 
               
               
                 6790 
                 White for Matting 
                   
                   
                   
                 X 
                   
                 X 
                 3, 6 
               
               
                   
               
             
          
           
               
                 New 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 No. 
                 Pinks, Crimsons, &amp; Corals 
                 Al 
                 Ca 
                 Cr 
                 Fe 
                 Mn 
                 Si 
                 Sn 
                 V 
                 Zn 
                 Zr 
                 See Ref. 
               
               
                   
               
               
                 6000 
                 Shell Pink 
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6001 
                 Alpine Rose 
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6002 
                 Rose Pink 
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6003 
                 Crimson 
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6004 
                 Crimson 
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6005 
                 Deep Crimson 
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6006 
                 Deep Crimson 
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6007 
                 Peach 
                   
                   
                 X 
                   
                   
                   
                 X 
                 X 
                   
                   
                 3, 5, 9 
               
               
                 6008 
                 Peach 
                   
                   
                 X 
                   
                   
                   
                 X 
                 X 
                   
                   
                 3, 5, 9 
               
               
                 6009 
                 Coral 
                   
                   
                 X 
                   
                   
                   
                 X 
                 X 
                   
                   
                 3, 5, 9 
               
               
                 6020 
                 Manganese Alumina 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                   
                 1, 3 
               
               
                 6023 
                 Clover Pink 
                   
                   
                 X 
                   
                   
                   
                 X 
                 X 
                   
                 X 
                 3, 5 
               
               
                 6029 
                 Persimmon 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 3, 8 
               
               
                 6031 
                 Deep Salmon 
                   
                   
                 X 
                 X 
                   
                   
                 X 
                   
                   
                   
                 3, 5 
               
               
                 6032 
                 Coral 
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                   
                 X 
                 3 
               
               
                 6052 
                 Doll Flesh 
                 X 
                   
                 X 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                 1, 3, 6 
               
               
                 6065 
                 Chrome Alumina 
                 X 
                   
                 X 
                   
                   
                   
                   
                   
                   
                   
                 1, 3, 6 
               
               
                 6067 
                 Pink Extender 
                   
                 X 
                   
                   
                   
                 X 
                 X 
                   
                   
                   
                 3, 5 
               
               
                 6069 
                 Dark Coral 
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                   
                 X 
                 3 
               
               
                 6090 
                 Coral 
                   
                   
                 X 
                   
                   
                   
                 X 
                 X 
                   
                   
                 3, 5, 9 
               
               
                 6098 
                 Flesh 
                   
                   
                 X 
                   
                   
                   
                 X 
                 X 
                   
                 X 
                 3, 5, 9 
               
               
                   
               
             
          
           
               
                 New 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 No. 
                 Yellows 
                 Al 
                 Cr 
                 Fe 
                 Pr 
                 Sb 
                 Si 
                 Sn 
                 Ti 
                 V 
                 Zn 
                 Zr 
                 See Ref. 
               
               
                   
               
               
                 6404 
                 Vanadium 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                 1, 3, 6 
               
               
                 6405 
                 Naples 
                   
                   
                 X 
                 X 
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 6 
               
               
                 6406 
                 Buttercup 
                   
                   
                 X 
                 X 
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 6 
               
               
                 6407 
                 Marigold 
                   
                   
                 X 
                 X 
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 6 
               
               
                 6408 
                 Praseodymium 
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 6 
               
               
                 6433 
                 Praseodymium 
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 6 
               
               
                 6440 
                 Vanadium 
                   
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                 1, 3, 6 
               
               
                 6450 
                 Praseodymium 
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                   
                   
                 X 
                 3, 6 
               
               
                 6464 
                 Zirconium 
                   
                   
                   
                   
                   
                   
                   
                 X 
                 X 
                   
                 X 
                 1, 3, 6 
               
               
                 6471 
                 Old Gold 
                 X 
                 X 
                 X 
                   
                   
                   
                 X 
                   
                 X 
                 X 
                   
                 1, 3, 6 
               
               
                 6485 
                 Titanium 
                   
                 X 
                   
                   
                 X 
                   
                   
                 X 
                   
                   
                   
                 1a, 3 
               
               
                   
               
             
          
           
               
                 New 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 No. 
                 Purples &amp; Lavenders 
                 Al 
                 Ca 
                 Co 
                 Cr 
                 Fe 
                 Mn 
                 Ni 
                 Si 
                 Sn 
                 V 
                 Zn 
                 Zr 
                 See Ref. 
               
               
                   
               
               
                 6303 
                 Deep Orchid 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6317 
                 Lavender 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 3, 5, 9 
               
               
                 6318 
                 Amaethyst 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 3, 5, 9 
               
               
                 6319 
                 Lavender 
                 X 
                   
                 X 
                   
                   
                 X 
                   
                 X 
                   
                   
                 X 
                   
                 1, 3 
               
               
                 6324 
                 Violet 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                 X 
                 X 
                   
                 X 
                 X 
                 3, 5, 9 
               
               
                 6331 
                 Orchid 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 3, 5, 9 
               
               
                 6332 
                 Orchid 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 3, 5, 9 
               
               
                 6333 
                 Lavender 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                 3, 5, 9 
               
               
                 6381 
                 Blackberry Wine 
                   
                   
                 X 
                 X 
                 X 
                   
                 X 
                 X 
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6385 
                 Pansy Purple 
                   
                   
                 X 
                 X 
                   
                   
                   
                 X 
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6387 
                 Mulberry 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                   
                   
                 3, 5, 9 
               
               
                 6392 
                 Dusty Lavender 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                 X 
                 X 
                   
                 X 
                 3, 5, 9 
               
               
                   
               
             
          
           
               
                 New 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 No. 
                 Browns &amp; Oranges 
                 Al 
                 Ca 
                 Co 
                 Cr 
                 Fe 
                 Mn 
                 Si 
                 Sn 
                 Ti 
                 V 
                 Zn 
                 Zr 
                 See Ref. 
               
               
                   
               
               
                 6100 
                 Woodland 
                 X 
                   
                   
                 X 
                 X 
                   
                 X 
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6101 
                 Chestnut 
                   
                   
                   
                 X 
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6103 
                 Golden 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6104 
                 Fawn 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                 X 
                   
                 X 
                 3, 6, 7 
               
               
                 6107 
                 Dk. Golden 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6108 
                 Walnut 
                   
                   
                   
                 X 
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6109 
                 Deep Brown 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6110 
                 Violet Of Iron 
                 X 
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                   
                   
                   
                 3, 6, 7 
               
               
                 6111 
                 Spice Brown 
                   
                   
                   
                   
                 X 
                   
                   
                 X 
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6113 
                 Claret 
                   
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6119 
                 Russet 
                   
                 X 
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                 X 
                 3, 6, 7 
               
               
                 6121 
                 Saturn Orange 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                   
                 3, 6, 7 
               
               
                 6122 
                 Cedar 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6123 
                 Saddle 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6124 
                 Chocolate 
                 X 
                   
                   
                 X 
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6125 
                 Leather 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6126 
                 Hazelnut 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 7 
               
               
                 6129 
                 Golden Ambrosia 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6131 
                 Titanium Iron 
                   
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 1a, 3, 6 
               
               
                 3132 
                 Red Brown 
                   
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 3133 
                 Sorrel Brown 
                   
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6134 
                 Red Brown 
                   
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6149 
                 Iron Silicate 
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                   
                   
                   
                 3, 6, 7 
               
               
                 6155 
                 Black Brown 
                   
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                   
                 3, 6, 7 
               
               
                 6153 
                 Seal Brown 
                   
                   
                   
                 X 
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6160 
                 Dk. Chocolate 
                 X 
                   
                   
                 X 
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6163 
                 Terra Cotta 
                 X 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6166 
                 Camel Beige 
                 X 
                   
                 X 
                 X 
                 X 
                 X 
                   
                   
                   
                   
                 X 
                   
                 3, 6, 7 
               
               
                 6190 
                 Deep Brown 
                   
                   
                   
                 X 
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                 3, 6, 7 
               
               
                 6194 
                 Manganese Silicate 
                   
                   
                   
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                 3, 6, 7 
               
               
                   
               
             
          
           
               
                 New 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 No. 
                 Greys 
                 Al 
                 Co 
                 Cr 
                 Fe 
                 Mn 
                 Ni 
                 Sb 
                 Si 
                 Sn 
                 Ti 
                 V 
                 Zr 
                 See Ref. 
               
               
                   
               
               
                 6500 
                 Sage 
                   
                 X 
                 X 
                   
                   
                 X 
                   
                 X 
                   
                   
                   
                   
                 1, 3, 6 
               
               
                 6503 
                 Taupe 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                 X 
                 3, 5, 9 
               
               
                 6506 
                 Pearl 
                   
                 X 
                 X 
                 X 
                   
                 X 
                   
                   
                 X 
                   
                   
                   
                 3, 6 
               
               
                 6515 
                 Soft Medium 
                 X 
                   
                 X 
                 X 
                 X 
                   
                   
                 X 
                   
                   
                   
                 X 
                 3, 5 
               
               
                 6523 
                 Soft Green 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                   
                 X 
                 X 
                   
                   
                 X 
                 3, 5 
               
               
                 6527 
                 Shadow 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                 X 
                 X 
                   
                   
                 X 
                 3, 5, 9 
               
               
                 6528 
                 Charcoal 
                   
                 X 
                 X 
                 X 
                   
                 X 
                   
                   
                 X 
                   
                   
                   
                 3, 6 
               
               
                 6530 
                 Silver 
                   
                 X 
                 X 
                 X 
                   
                 X 
                   
                   
                 X 
                   
                   
                   
                 3, 6 
               
               
                 6531 
                 Slate 
                   
                 X 
                 X 
                 X 
                   
                 X 
                   
                   
                 X 
                   
                   
                   
                 1, 3, 6 
               
               
                 6537 
                 Mouse 
                 X 
                   
                 X 
                 X 
                   
                   
                   
                 X 
                 X 
                   
                   
                 X 
                 3, 5, 9 
               
               
                 6540 
                 Blue-Grey 
                   
                 X 
                 X 
                 X 
                   
                 X 
                   
                   
                 X 
                   
                   
                   
                 3, 6 
               
               
                 6572 
                 Neutral 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                   
                   
                   
                 X 
                 3, 5 
               
               
                 6573 
                 Rose Taupe 
                   
                   
                 X 
                 X 
                   
                   
                   
                   
                 X 
                 X 
                 X 
                 X 
                 3, 5, 9 
               
               
                 6584 
                 Tin Grey 
                   
                   
                   
                   
                   
                   
                 X 
                   
                 X 
                   
                   
                   
                 2, 8 
               
               
                 6591 
                 Gun Metal 
                   
                 X 
                   
                   
                   
                 X 
                   
                   
                   
                   
                   
                 X 
                 3, 6 
               
               
                   
               
             
          
         
       
     
     Reference Notes For Color Composition Charts 
     1. Can be used as a ‘body stain’ in porcelain at high temperatures. All of the brown colors can be used as ‘body stains’ but will vary in shade considerably depending on the composition of the body and temperature at which it is fired. 
     1a. Use only as ‘Body Stain’ 
     Firing Temperatures can only be a rough guide. Firing at 2200° F. on a slow schedule may give the equivalent maturing as firing at 2300° F. on a fast schedule. The cycle, atmosphere, and rate of cooling will affect the color. 
     2. Max. firing limit 2156° F. (1180° C.). 
     3. Max. firing limit 2300° F. (1260° C.). 
     4. Max. firing limit 1976° F. (1080° C.). 
     Zinc Oxide influences the color in a glaze more than any other element. Generally, zincless glazes should not contain magnesium oxide. Some colors containing zinc are to be used in a zincless glaze. The zinc in the color is in a combined form and will not harm the color, but free zinc oxide in the glaze can destroy the color. 
     5. Do not use zinc in glaze. 
     6. May be used with zinc or without zinc. 
     7. Zinc not necessary, but gives better results. 
     8. Best results with no zinc. 
     Calcium Oxide content as calcium carbonate should be from 12-15% for best color development. Adding the molecular equivalent of calcium oxide with wollastonite, a natural calcium silicate, often gives better uniformity. The increased silica from the wollastonite must be subtracted or the glaze will have a poor surface. 
     9. Glaze must contain from 6.7 to 8.4% CaO (12-15% CaCO 3 ) 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Metal to Metal Oxide Conversion Key for Color Composition Charts 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Al 
                 Aluminum Oxide 
                 Al 2 O 3   
               
               
                 B 
                 Boric Oxide 
                 B 2 O 3   
               
               
                 Ca 
                 Calcium Oxide 
                 CaO 
               
               
                 Co 
                 Cobalt Oxide 
                 CoO 
               
               
                 Cr 
                 Chromium Oxide 
                 Cr 2 O 3   
               
               
                 Fe 
                 Iron Oxide 
                 Fe 2 O 3   
               
               
                 Mn 
                 Manganese Dioxide 
                 MnO 2   
               
               
                 Ni 
                 Nickel Oxide 
                 NiO 
               
               
                 Pr 
                 Praseodymium Oxide 
                 Pr 6 O 11   
               
               
                 Sb 
                 Antimony Oxide 
                 Sb 2 O 3   
               
               
                 Si 
                 Silicon Dioxide 
                 SiO 2   
               
               
                 Sn 
                 Tin Dioxide 
                 SnO 2   
               
               
                 Ti 
                 Titanium Dioxide 
                 TiO 2   
               
               
                 V 
                 Vanadium Pentoxide 
                 V 2 O 5   
               
               
                 Zn 
                 Zinc Oxide 
                 ZnO 
               
               
                 Zr 
                 Zirconium Dioxide 
                 ZrO 2   
               
               
                   
               
             
          
         
       
     
     Refractory metal oxides are metal oxides stable in air at a temperature of at least 1600° F., preferably at least 1800° F., more preferably at least 1976° F., most preferably at least 2700° F. Here, the term “refractory” means stable in air at temperatures of at least 1600° F., and “stable” means without significant color degradation after heating in air to the specified temperature and cooling to room temperature. 
     Mesh is a way to define the diameter of a particle by the size of interstitial site in a wire mesh through which the particle will pass. For example, 200 mesh particles will pass through the interstices of a wire screen with 200 wires per inch. Since the particle size that will pass through a screen decreases with increasing mesh number, particles defined as 200 mesh will contain all those capable of passing through a 200 wire per inch screen and smaller. Two-hundred mesh particles contain 400 mesh, but not 100 mesh. 
     Since mesh is not a direct measurement of individual particles, but a characteristic of those that can pass through a specific screen, it is best thought of as representing the average particle diameter of all the particles that pass through the screen, averaged. Fifty mesh particles preferably have an average particle diameter of from 254 to 297 microns. One-hundred mesh particles preferably have an average particle diameter of 22 to 149 microns. Two-hundred mesh particles preferably have an average particle diameter of 40 to 85 microns, more preferably 45 to 80 microns, and most preferably 50 to 74 microns. Four-hundred mesh particles have an average particle diameter of 5 to 47 microns, preferably 10 to 42 microns, and most preferably 15 to 37 microns. 
     EXAMPLES 
     Example 1 
     Five grams of silver jewelry-metal clay was weighed and handled in accordance to information provided by MITSUBISHI MATERIALS CORPORATION. After shaping three separate five gram clay samples into pancake-like forms, 0.1 gram of refractory stain was added to the first, 0.3 gram to the second, and 0.5 gram to the third. Each sample was kneaded until the refractory stain was thoroughly distributed throughout the jewelry-metal clay. A droplet of water was added to ease kneading of the 0.3 and 0.5 gram stain addition samples. 
     The jewelry-metal clay samples containing the refractory stain were each rolled into an oval sheet and weighed. The samples were allowed to thoroughly dry before firing, and their dry weights recorded. 
     The samples were fired on an earthenware tile, dusted with clean alumina hydrate. The tile was stilted and placed in an electronically monitored electric kiln. The samples were fast-fired according to MITSUBISHI MATERIALS CORPORATION&#39;s specifications (1650° F. for two hours). The kiln was allowed to cool before the samples were removed. The fired samples were weighed and the weights recorded. 
     The samples were successfully colored with the color of the chosen refractory stain. The color was perfectly distributed. The sample containing the highest concentration (0.5 gram or 10% by weight) of refractory stain provided a darker colored silver article. The sample containing the lowest concentration (0.1 gram or 2% by weight) of refractory stain provided a lightly colored silver article. The resultant articles were malleable, like uncolored jewelry-metal clay sintered articles. The resultant articles demonstrated shrinkage, like uncolored jewelry-metal clay sintered articles, but showed no additional deformation or loss of detail in comparison to uncolored articles. 
     Prophetic Example 1 
     Five grams of gold jewelry-metal clay is weighed and handled in accordance to information provided by MITSUBISHI MATERIALS CORPORATION. After shaping three separate five gram clay samples into pancake-like forms, 0.1 gram of refractory stain is added to the first, 0.3 gram to the second, and 0.5 gram to the third. Each sample is kneaded until the refractory stain is thoroughly distributed throughout the jewelry-metal clay. A droplet of water is added to ease kneading of the 0.3 and 0.5 gram stain addition samples. 
     The jewelry-metal clay samples containing the.refractory stain are each rolled into an oval sheet and weighed. The samples are allowed to thoroughly dry before firing, and their dry weights recorded. 
     The samples are fired on an earthenware tile, dusted with clean. alumina hydrate. The tile is stilted and placed in an electronically monitored electric kiln, The samples are fast-fired according to MITSUBISHI MATERIALS Corporation&#39;s specifications (1830° F. for two hours). The kiln is allowed to cool before the samples are removed. The fired samples are weighed and the weights recorded. 
     Prophetic Example 2 
     A five gram sample of finely ground silver is weighed. One-half gram of refractory stain is added and thoroughly mixed with the silver powder. The powdered mixture of silver and refractory stain is pressed into a cylinder and fired in an electronically monitored electric kiln at 1470° F. for thirty minutes. The kiln is allowed to cool before the sample is removed. The colored silver mass is then removed and could be shaped into the desired item with hand tools, machine, or die. The colored silver could also be hammered or drawn into wires. 
     Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.