Method for enhancing the color of minerals useful as gemstones

Abstract

In accordance with the present invention, there are provided methods for enhancing the color of minerals useful as gemstones. Invention methods are relatively inexpensive to carry out, avoid the use of hazardous materials, and require no specialized equipment.

That which is claimed is:  
     
         1 . A method for enhancing the color of gemstones, said method comprising: 
 subjecting a combination of a gemstone and at least one non-alumina treating agent, wherein said treating agent comprises a finely divided form of cobalt or cobalt oxide to conditions suitable to enhance the color of said gemstone, without causing a significant level of surface damage to said gemstone.    
     
     
         2 . A method according to  claim 1  wherein said gemstone is selected from topaz, chrysoberyl, sapphire, quartz or garnet.  
     
     
         3 . A method according to  claim 1  wherein said treating agent is cobalt.  
     
     
         4 . A method according to  claim 1  wherein said treating agent is cobalt oxide.  
     
     
         5 . A method according to  claim 1  wherein said gemstone is cleaned prior to being subjected to said conditions suitable to enhance the color of said gemstone.  
     
     
         6 . A method according to  claim 1  wherein said conditions suitable to enhance the color of said gemstone comprise subjecting said combination to a temperature in the range of about 825° C. up to about 1050° C., for a time in the range of about 3 up to about 200 hours.  
     
     
         7 . A method according to  claim 1  further comprising subjecting said gemstone to a temperature in the range of about 825° C. up to about 1050° C. for a length of time in the range of about 3 up to about 200 hours in the absence of said treating agent.  
     
     
         8 . A method according to  claim 1  wherein said gemstone is cleaned after being subjected to said conditions suitable to enhance the color of said gemstone.  
     
     
         9 . A color enhanced gemstone prepared by the method of  claim 1 .  
     
     
         10 . A color enhanced gemstone comprising a gemstone having a color enhancing agent diffused into the outer surface thereof.  
     
     
         11 . A color enhanced gemstone comprising a gemstone wherein at least the surface thereof has chemically bonded thereto a color enhancing agent.