Method for engraving irreproducible pattern on the surface of a diamond

Abstract

The present invention provides a method for engraving desired irreproducible patterns on the surface of gemstones including diamond by the use of an energetic ion beam. The pattern has a characteristic topological texture, which is irreproducible even using the same ion beam to engrave onto the same location of the same diamond.

1 . A method for engraving an irreproducible pattern on the surface of a diamond, comprising the step of: 
 exposing an energetic ion beam onto the surface of the diamond at an angle from the normal of the surface of about 45°-85°.    
   
   
       2 . The method according to  claim 1  wherein the angle is of about 50°-70°.  
   
   
       3 . The method according to  claim 1  wherein the angle is of about 55°-65°.  
   
   
       4 . The method according to  claim 1  wherein the angle is of about 60°.  
   
   
       5 . The method according to  claim 1  further comprising the step of engraving a second pattern on the surface of the diamond.  
   
   
       6 . A method according to  claim 5  wherein the size of the entire said second pattern can be as large as the area of the surface of the diamond.  
   
   
       7 . The method according to  claim 5  wherein said second pattern is at least one selected from the group consisting of a photograph, printed character, drawing, and signature.  
   
   
       8 . The method according to  claim 1  wherein said energetic ion beam is a focused ion beam.  
   
   
       9 . The method according to  claim 8  wherein the diameter of said focused ion beam is about 5 nm.  
   
   
       10 . A method for engraving an irreproducible pattern on the surface of a diamond, comprising the steps of: 
 positioning a mask between an output of an ion beam and the surface of the diamond; and    exposing the ion beam on the exposed area of the mask at an angle from the normal of the surface of about 45°-85°.    
   
   
       11 . The method according to  claim 10  wherein the angle is of about 50°-70°.  
   
   
       12 . The method according to  claim 10  wherein the angle is of about 55°-65°.  
   
   
       13 . The method according to  claim 10  wherein the angle is of about 60°.  
   
   
       14 . The method according to  claim 10  wherein the step of positioning a mask comprises the steps of: 
 covering the surface of the diamond with a resist layer; and    removing selected portion of the resist layer to expose an area to said energetic ion beam.    
   
   
       15 . The method according to  claim 10  wherein said energetic ion beam is a broad ion beam.  
   
   
       16 . The method according to  claim 15  wherein said broad ion beam is Ar+.  
   
   
       17 . A diamond having a surface on which is a pattern has been applied using the method comprising the step of: 
 exposing an energetic ion beam onto the surface of the diamond at a angle from the normal of the surface of about 45°-85°.    
   
   
       18 . A method of authenticating an object comprising permanently attaching to the object a diamond according to  claim 17.