Fine gold articles

Structurally strong, investment quality gold articles of high troy weight, excellent color and revealing properties and the method of their production are described, including the formation of a structural base from an alloy containing not over 8% of a strengthening material such as chromium, titanium or vanadium, which can provide the required strength and hardness in low concentrations, and overlayment or "overaching" with a gold alloy coating in a manner such that both alloys are visible. The structural base provides the support, strength and resistance to corrosion in articles of various shapes, while retaining a high degree of gold fineness.

BACKGROUND OF THE INVENTION 
1. Field of The Invention 
This invention relates to the manufacture of hitherto nonexistent 
beautiful, investment quality gold articles and adornments of extremely 
high purity, yet capable of being worn and otherwise used. 
2. Description of the Prior Art 
Known and highly valued from the earliest times, gold is the most malleable 
and ductile metal. One ounce can be pounded to provide 300 sq. ft. of gold 
leaf with which to adorn large pieces of artwork or architecture or drawn 
into 60 miles of wire. 
It is well known that gold has to be alloyed for strength. Steel and other 
metal objects can be gold plated, but as an investment, these objects are 
worthless. Gold alloys are used to produce wearable gold articles. 
Sometimes gold alloys are laminated to produce a beautiful piece of 
jewelry of a desired grade of fineness on its outer shell, but containing 
a filler of much lower value. 
Burdon, U.S. Pat. No. 440,693, describes a method of manufacturing seamless 
compound gold wire which can be molded into articles of jewelry and sold 
as gold of a specified value or carat. This value represents the average 
of the higher content gold shell and the lower content internal filler. 
Articles produced by Burdon's method still suffer from low purity and lack 
of uniformity when considering jewelry as an investment, averaging around 
9 carats. Furthermore, the consumer is not readily able to ascertain the 
gold content of the entire piece, and abuses have been common. 
Fry, U.S. Pat. No. 1,704,126, describes a process whereby a thin layer of 
platinum is laminated to a surface of gold alloy stock which comprises a 
softer inner gold-copper alloy layer, which is workable with jeweler's 
tools, and a gold-nickel outer layer, which possesses good color. To 
achieve a 14 carat average value for the gold stock, Fry uses a thick 
inner layer of 13.5 karat fineness gold-copper alloy, and a thin layer of 
20 karat fineness gold-nickel. To obtain a 14 karat fineness average 
value, Fry does little more than plate the core with the finer alloy, the 
ratio being approximately 21:1. While the outer coating prevents 
tarnishing and imparts a beautiful color, the concept still does not 
relate to producing quality gold jewelry. 
What is needed is a method of producing gold articles which have the 
luxurious appearance and extreme fineness of nearly pure gold, and the 
strength to be wearable or otherwise useable. To be of investment quality, 
such articles must also be readily appraisable. If only it were possible 
to construct durable articles of nearly solid gold. The present disclosure 
presents a solution. Described herein is a method of manufacturing 
beautiful, investment quality, wearable and otherwise useable gold 
articles with a hitherto unavailable troy weight of 22 karat fineness or 
more. 
SUMMARY OF THE INVENTION 
This invention is an article of structurally strong, investment quality 
gold articles of high troy weight, excellent color and revealing 
properties, comprising: an investment quality gold alloy base of at least 
22 karat fineness comprising gold alloyed with at least one additional 
element which is present in sufficient concentration to impart strength to 
said alloy but not to exceed 8% of this alloy; and a gold alloy coating 
also of at least 22 karat fineness surrounding and affixed to all but one 
side of said base; the relative proportions of said base and said coating 
being readily discernible from the uncoated portion of the base. 
Also part of this invention is a method of producing gold articles of 
investment quality, comprising the steps of: producing a gold alloy of at 
least 22 karat fineness and comprising gold alloyed with another element 
which enhances the strength of said alloy, said element being present in 
an amount sufficient, up to 8% of said alloy, to enhance said strength; 
overlaying said base on all but one side with a coating of a second gold 
alloy of at least 22 karat fineness and bonding said base and said coating 
to form a uniform article, the relative proportion of said base and said 
coating readily determined by examining the uncoated part of said base. 
In a method of producing articles from gold alloys, this invention provides 
an improvement whereby investment quality articles of 22 karat fineness or 
more are produced by the steps comprising constructing a base of 22 or 
more karat fineness comprising gold alloyed with another element which 
enhances the strength of said alloy, each element being present in an 
amount sufficient, up to 8% of said alloy, to enhance said strength; and 
overlaying said skeleton on all sides but one with a gold alloy coating of 
22 or more karat fineness, the base and coating being readily visible from 
the uncoated side. 
Thus, gold jewelry and other articles are produced where the structural 
base layer is not hidden but incorporated into an attractive and 
informative pattern, yielding something like a cross-sectional 
perspective. Other embodiments of the present invention need not 
specifically require that the coating alloy cover all sides readily 
visible without examination. For example, the structural base and the 
coating can be disposed relative to each other in a manner to take 
advantage of the beauty of the colors imparted by each of them. 
Although chromium, titanium and vanadium have been discovered nearly two 
hundred years ago or more, and have been used in alloys with other metals, 
to the Applicant's knowledge, they have not been alloyed with gold to 
produce articles described here. These elements have the specific 
properties of strength and hardness required in the structural base in 
such low concentrations.

DETAILED DESCRIPTION OF THE INVENTION 
Referring more particularly to the drawings, FIGS. 1 and 2 schematically 
illustrate the concept of this invention. FIG. 1 depicts the outside 
surface of a ring, displaying a uniform, fine structured gold alloy. FIG. 
2, however, shows that the ring is not of a uniform character, but is in 
fact composed of a core or base 3 and an overlying abutting noncontinuous 
coating layer 2. The core or base, which serves as a structural support 
member, comprises an alloy having at least two elemental components, one 
component of which is a hard metal added for the specific purpose of 
strengthening the entire structure. The other component is pure 24 karat 
fineness gold. 
It is critical to this invention that the coating layer coats or clads more 
than half, and preferably most surfaces of all sides except the back, of 
the jewelry article, so that the coating "arches over" and is fully 
supported by the base layer. The idea here is not to use the core as a 
filler with an inferior gold alloy, as is practiced in the prior art, but 
to use a strengthener which is effective in small amounts in order to 
maintain a high quality 22+ karat fineness structure throughout the 
article while yet providing a high strength alloy base to support the 
outer coating layer. In order to retain the near-pure gold composition, 
the strengthener must be present and effective in concentrations of or 
below 8%. If the alloy is other than binary, the concentration of 
strengthener must be adjusted to compensate. 
The unclad surface of the jewelry article need not always be hidden from 
view or on the underside. In an alternate embodiment, if the two alloys 
are of different colors, this structural aspect can be exploited to 
produce jewelry in variant attractive color patterns, keeping in mind the 
purpose of the unclad side so as not to distort consumer perception. 
The use of pure gold as an overwhelmingly major component of an alloy 
teaches away from having to choose inferior metals for their workability 
properties resulting in low quality jewelry. Being the most malleable and 
ductile metal, gold can tame the hardness and brittleness of the added 
strengthener, and does not have to be replaced by copper or some other 
previously used metal for these workability properties. 
FIG. 3 is a top plan view of a gold brooch 4 constructed in the manner 
defined by this invention. The uniform outer coating 2 covers an 
underlying supporting structural base 3. As stated above, it is envisioned 
that in another embodiment the layers could be combined in a manner where 
the base structural layer is not covered by the coating layer, but where 
the two layers are exposed, for example, in a banded arrangement, if the 
effect were aesthetically pleasing. In other words, the supporting 
structural base could be revealed by positioning it to be visible, e.g. 
topmost, while retaining its supportive function. In all cases the 
thickness of the overlying coating preferably is uniform. 
The two layers constituting the gold jewelry can be joined or bonded in any 
conventional manner known and practiced by those skilled in the art, 
including "sweating" or welding, cementing or merely sheathing if 
appropriate. 
It will be appreciated that, regardless of the proportions of the two 
alloys, the overall value or carat rating is 22 karat fineness or more, 
since both alloys are high quality, 22 karat fineness or better, and the 
rating for the jewelry article is not attained by averaging a low rated 
filler and a high rated thin shell as commonly found in the prior art.