Abstract:
Methods of fabricating improved gemstones and gemstones thus obtained are described. Roughness is introduced on facets of a gemstone through application of nanometer and/or micrometer sized features, to provide the facets with a hazy white-colored appearance. Alternatively, millimeter-sized reflective features can be applied on the facets, to form a gemstone with improved scintillation or play of light.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation in-part of U.S. Ser. No. 11/635,386, filed on Dec. 6, 2006, entitled “Enhancing the Optical Characteristics of a Gemstone” which is incorporated herein by reference and also attached to the specification of the present application as Annex A. Annex A forms part of the specification of the present application. The present application also claims priority from provisional application Ser. No. 61/005,063 filed on Nov. 30, 2007 entitled Technique to Improve Diamond White Light Return herein incorporated by reference in its entirety. 
    
    
     FIELD 
     The present disclosure relates to gemstones, in particular to methods of fabricating improved gemstones and gemstones thus obtained. 
     BACKGROUND 
     The above mentioned U.S. Ser. No. 11/635,386 describes methods for increasing brilliance and/or fire of a gemstone (e.g., diamond) using a combination of periodic nano- and micro-sized features, which form a diffractive optical element disposed on or in the body of the gemstone. Each size produces its own effect in the light path of the gemstone. 
     SUMMARY 
     Provided herein, are gemstones and related methods and systems for controlling the appearance thereof, which in certain embodiments can increase brilliance and/or fire of the gemstone using a combination of nano, micro and/or milli size features. 
     According to a first aspect of the present disclosure, a method for controlling appearance of a gemstone comprising a plurality of facets is provided. The method comprises: introducing roughness on one or more of the facets through application of nanometer and/or micrometer sized features on the one or more facets, to provide the one or more facets with a hazy white-colored appearance. 
     According to a second aspect of the present disclosure, a method of controlling appearance of a gemstone comprising a plurality of facets is provided. The method comprises: forming millimeter-sized reflective features on each facet, in particular according to one or more techniques shown in Annex A. 
     According to a third-aspect of the present disclosure, a gemstone comprising a plurality of facets is provided. In the gemstone one or more of the facets have a hazy white-colored appearance associated with nanometer and/or micrometer sized features on said facets. 
     According to a fourth aspect of the present disclosure, a gemstone comprising a plurality of facets is provided. In the gemstone, each facet is a reflective facet through formation of millimeter-sized features on said each facet, and the gemstone has an improved scintillation or play of light. 
     Further aspects and embodiment of the present disclosure are disclosed in the specification, drawings and claims of the present application. The details of one or more embodiments of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more embodiments of the present disclosure and, together with the detailed description, serve to explain the principles and implementations of the disclosure. 
         FIG. 1  shows a flowchart illustrating a method for controlling appearance of a gemstone according to some embodiments herein disclosed. 
         FIG. 2  shows a flowchart illustrating a method for controlling appearance of a gemstone according to some embodiments herein disclosed. 
         FIG. 3  shows a flowchart illustrating a method for controlling appearance of a gemstone according to some embodiments herein disclosed. 
         FIG. 4  shows a flowchart illustrating a method for controlling appearance of a gemstone according to some embodiments herein disclosed. 
     
    
    
     DETAILED DESCRIPTION 
     Gemstones and related methods and systems for controlling appearances thereof are provided herein. 
     A first aspect presented in the present application is that of introducing roughness in the gemstone to make the stone look hazy and, in particular, white-colored. Reference is made to the flowchart of  FIG. 1 . In particular, roughness in the form of non periodic nano- and/or micro-features, can be introduced in the gemstone by way of etch parameters and/or random surface masking techniques. In some embodiments the non-periodic nano- and/or micro-features introduced in the gemstone are random nano and/or microfeatures applied to one or more facets of the gemstone, or sections thereof, through etching and/or masking techniques. Etching of a gemstone is disclosed, for example, in paragraphs [0040], [0046], [0052], [0083] and [0093] of Annex A. Masking techniques in association with a gemstone are disclosed, for example, in paragraphs [0077]-[0080], [0084], [0088]-[0090], [0092], [0093], [0095], [0096], and [0098]-[0101] of Annex A. 
     In particular, the gemstone can be patterned to comprise different shapes, similarly to an etched glass, each shape having a random surface roughness and providing a hazy (i.e., cloudy) white light output. Roughness can be introduced on one or more facets of the gemstone and/or sections of the facets, in particular by applying the non-periodic nano- and or micro-feature to one or more millimeter sized feature on one or more facets of the gemstone. 
     According to a further aspect of the present application, features larger than nano- or micro-features are introduced, on the order of a millimeter. Such features can either act as diffractive features, or act as individual reflectors/mirrors if introduced through smoothening, polishing or etching steps disclosed, by way of example, in Annex A. This effect is called scintillation. Reference is made to the flowchart of  FIG. 2 . 
     When millimeter-sized smooth features are introduced, the gemstone will have a disco ball effect, i.e. a roughly prismatic object having a surface made of a plurality of facets having a mirrored surface, with a great increase in brilliance and scintillation. 
     According to a further aspect of the present application, the millimeter-sized reflective facets of the previous embodiment can be combined with periodic nano- or micro-features or with non-periodic, and in particular random, nano- or micro-features. In the first case, a non-white-colored disco ball effect will be obtained (e.g., “crazy color” disco ball) while, in the second case, a white-colored disco ball effect will be obtained. Reference is made to the flowcharts of  FIGS. 3 and 4 . 
     More specifically, a first pass is initially performed to make larger, millimeter-scale facets ( FIGS. 3 and 4  S 1 ), and then a second pass is performed, to put diffraction (by applying periodic nano- or micro-sized features) ( FIGS. 3  S 2 ) or haziness (by applying non-periodic, and in particular random, nano- or micro-sized features) on the millimeter-size facets ( FIG. 4  S 3 ). 
     The examples set forth above are provided to give those of ordinary skill in the art a complete disclosure and description of how to make and use the embodiments of the gemstones, methods and systems of the disclosure, and are not intended to limit the scope of what the inventors regard as their disclosure. Modifications of the above-described modes for carrying out the disclosure that are obvious to persons of skill in the art are intended to be within the scope of the following claims. All patents and publications mentioned in the specification are indicative of the levels of skill of those skilled in the art to which the disclosure pertains. All references cited in this disclosure are incorporated by reference to the same extent as if each reference had been incorporated by reference in its entirety individually. 
     The entire disclosure of each document cited (including patents, patent applications, journal articles, abstracts, laboratory manuals, books, or other disclosures) in the Background, Summary, Detailed Description and Annex A is hereby incorporated herein by reference. 
     It is to be understood that the disclosures are not limited to particular compositions or systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. The term “plurality” includes two or more referents unless the content clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure pertains. 
     Although any methods and materials similar or equivalent to those described herein can be used in the practice for testing of the specific examples of appropriate materials and methods are described herein. 
     A number of embodiments of the disclosure have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the present disclosure. Accordingly, other embodiments are within the scope of the following claims.