Methods, apparatus, and systems for evaluating gemstones

• US 7,420,657 B2
• Filed: 12/20/2004
• Issued: 09/02/2008
• Est. Priority Date: 12/22/2003
• Status: Active Grant

• Current Assignee: Gemological Institute of America Incorporated
• Original Assignee: American GEM Society
• Inventors: Sasian, Jose, Yantzer, Peter, Caudill, James
• Primary Examiner(s): Lauchman; Layla G.
• Assistant Examiner(s): Skovholt; Jonathan
• Application Number:
  US11/018,742
• Publication Number:
  US 20050200834A1
• Time in Patent Office: 1,352 Days
• Field of Search: None
• US Class Current: 356/30
• CPC Class Codes: G01N 21/00 Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light G01N3/00 - G01N19/00 take precedence
• CPC Class Codes: G01N 21/01 Arrangements or apparatus for facilitating the optical investigation
• CPC Class Codes: G01N 21/87 Investigating jewels G01N21/88 takes precedence
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features

Abstract

Methods for grading gemstones, apparatus for grading gemstones, and systems that utilize such methods and apparatus are disclosed.

Claims

1. A computer-implemented method, comprising:

generating a representation corresponding to an illuminated image of a gemstone viewed from an observation location, wherein said representation differentiates between light rays incident on said gemstone from a first range of incident angles and light rays incident on said gemstone from a second range of incident angles;

evaluating said gemstone based on light rays said gemstone directs to said observation location which were incident on said gemstone from an angle within said first range of incident angles; and

providing results from said evaluating to a user;

wherein said gemstone is evaluated based on light rays of a first wavelength said gemstone directs to said observation location which were incident on said gemstone from an angle within said first range of incident angles and on light rays of a second wavelength the gemstone directs to said observation location which were incident on said gemstone from an angle within said first range of incident angles.

2. The method of claim 1, wherein said gemstone is evaluated based on a difference between said light rays of said first wavelength and said light rays of a second wavelength.

3. A computer-implemented method, comprising:

generating a representation corresponding to an illuminated image of a gemstone viewed from an observation location, wherein said representation differentiates between light rays incident on said gemstone from a first range of incident angles and light rays incident on said gemstone from a second range of incident angles;

evaluating said gemstone based on light rays said gemstone directs to said observation location which were incident on said gemstone from an angle within said first range of incident angles; and

providing results from said evaluating to a user;

wherein a first color in the representation corresponds to light rays directed by the gemstone to the observation location which were incident on said gemstone from an angle within said first range of incident angles.

4. The method of claim 3, wherein the first range of incident angles corresponds to light incident on said gemstone from latitudinal angles from about 45°

to about 75°

with respect to a hemispherical reference frame.

5. The method of claim 3 wherein said evaluating is based on the proportion of said representation which is said first color.

6. The method of claim 3 wherein a second color in said representation corresponds to light rays directed by the gemstone to the observation location which were incident on said gemstone from an angle within said second range of incident angles;

and wherein said first color and said second color are different and said first range and said second range are mutually exclusive.

7. The method of claim 6, wherein said second range corresponds to light incident on the gemstone from latitudinal angles from about 75°

to about 90°

with respect to a hemispherical reference frame.

8. The method of claim 6 wherein said evaluating is based on the proportion of said representation which is said first color compared to the proportion of said representation which is said second color.

9. The method of claim 6 further comprising:

a third color in said representation, said third color corresponding to light rays directed by the gemstone to the observation location which were incident on said gemstone from an angle within a third range of incident angles;

wherein said first color, said second color, and said third color are different and said first range, said second range, and said third range are mutually exclusive.

10. The method of claim 9, wherein said third range of ray directions corresponds to light incident on the gemstone from latitudinal angles from about 0°

to about 45°

with respect to a hemispherical reference frame.

11. The method of claim 9 wherein said evaluating is based on the proportion of said representation which is said first color compared to the proportion of said representation which is said second color or said third color.

12. The method of claim 9 wherein said evaluating is based on the proportion of said representation which is said first color or said second color compared to the proportion of said representation which is said third color.

13. The method of claim 9, wherein said first color, said second color, and said third color are complimentary colors.

14. The method of claim 13, wherein said first color is red, said second color is blue, and said third color is green.