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Diamond Ring Buying Guide by Renee Newman
Consumer-oriented book filled with useful information, drawings & pictures for 1st time diamond buyer.

Photo Masters of Diamond Grading by Gary Roskin
Photo Masters is a compilation of 244 extraordinary photomicrographs, suitable for students or experienced diamond graders.

Blood Diamonds

Blood Diamonds cost torture & death for Sierra Leone residents. Conflict Diamonds finance civil wars & terrorists, including al Qaeda.

Antique Price Guide

By Judith Miller, author of more than 80 books on antiques, including "How to Make Money Out of Antiques."

 

GIA vs AGS Grading System for Cut

Below are tables showing the GIA (Gemological Institute of America) and the AGS (American Gem Society) grading system for cut.

GIA:

Class 1 2 3 4
Table 53% - 60%
(stones under 0.50 ct.
may go to 62%)
61% - 64% 51% - 52%
65% - 70%
- 51%
70% +
Crown 34 - 35 32 - 34 30 - 32
36 - 37
- 30
37 +
Girdle medium - sl. thick thin - thick v. thin -
v. thick
ext. thin -
ext. thick
Pavillion 43% 42% - 44% 41%
45% - 46%
- 41% or
46% +
Culet none - medium sl. large large very large
Finish very good - excellent good fair poor

 

Please note, a Diamond with major Symmetry variations may be placed in Class 4 as well.

 

AGS:

GRADE Table Diameter Crown Angle Girdle Pavillion Depth% Culet
0 53%-57% 34-35.5 Thin,
Medium,
Sl.Thick
42.5% - 43.5% Pointed,
Very Small, Small, Medium
1 52%,
58%-59%
33-33.5
36
Very Thin 44% Slightly Large
2 60%-61% 32.5, 36.5   42%, 44.5%  
3 51%,
62%-63%
32, 37 Thick   Large
4 64%-65% 31.5, 37.5   41.5%  
5 50%
66%-67%
31, 38 Very Thick 41%, 45% Very Large
6 68%-69% 30.5, 38.5   46%  
7 49%,
70%-71%
30, 39 Ext.Thin,
Ext.Thick
40.5%, Extremely Large
8 48%,
72%-73%
29.5, 39.5 Ext.Thick 40%, 47% Extremely Large
9 47%,
74%-75%
29 Ext.Thick -39%, 48% Extremely Large
10 -47%,
75%+
-29, 39.5+ Ext.Thick - 39%,
49% +
Extremely Large

 

Next let's discuss - Diamond Certificate vs. Diamond Appraisal-------------->

 







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