Identifying Synthetic Diamonds
Step 5: Advanced Gem Information Lesson 2 Back to syllabus Synthetic diamonds aren’t new. General Electric (GE) has been making them since…
Grading Gem Carvings
Gem carvings vary widely in size, shape, and quality. You can find small, simple carvings with a glued-on bail for just a couple of dollars. Fine…
Evaluating Gem Color: Hue, Tone, and Saturation
What color is the gem on the left? If you answered red, you’re wrong. It’s orange. Most people think the color of the gem on the right…
Color Grading White Diamonds
Step 4: Gem Grading Lesson 13 Back to syllabus “White,” 14kt white gold ring set with one 1.05-ct diamond and 6 10-pt diamonds, by Mark Somma.…
Color Grading Fancy Colored Diamonds
Step 4: Gem Grading Lesson 14 Back to syllabus Diamonds come in every color of the rainbow. Our standard white diamonds are either colorless or tinted…
Opal Buying Guide
Step 4: Gem Grading Lesson 18 Back to syllabus Gemologists evaluate opals a little differently than other gemstones. The traditional Four Cs still…
Disclosing Enhancements: A Gemologist’s Guide
Disclosing enhancements is one of the most important responsibilities gemologists face. In fact, many countries are passing stricter laws…
Gemology Cheat Sheets
Use these gemology cheat sheets to review color and clarity grading, as well as special information on diamond and opal. You can also review basic…
Refractometer Guide, Part 2: Cabochon Testing
Step 3: Practical Gemology Lesson 5 Back to syllabus You can use a refractometer to determine the refractive indices (RI) of most cabochons and…
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