Phenomenal Gems – Unique Phenomena in Gemstones
Some optical effects in gemstones, such as color, brilliance, and dispersion, can be quite impressive. However, not all optical effects are considered…
Appraising Gems and Jewelry
Step 6: Appraising Lesson 2 Back to syllabus Appraising gems and jewelry involves giving an opinion of value. If you take a pair of earrings to a jewelry…
Carats and Gemstone Grading
Step 4: Gem Grading Lesson 2 Back to syllabus A carat is the standard unit of measurement for weighing gems, and it’s one of the Four Cs of gemstone…
How to Grade Set Gemstones
Step 4: Gem Grading Lesson 4 Back to syllabus Few gemologists deal strictly with loose stones. Occasionally, most may have to grade set gemstones.…
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…
Clarity Grading for Colored Gemstones
Don’t underestimate the importance of clarity, one of the Four Cs of gemstone grading. For faceted gems, basic clarity grading involves…
Distinguishing Diamonds: Educating Your Eyes
Step 4: Gem Grading Lesson 10 Back to syllabus Distinguishing diamonds from their lookalikes is a prerequisite to diamond grading. Assigning…
The Art and Science of Identifying Gemstones
Trigon inclusions are part of a natural, uncut diamond’s original crystal structure. These were photographed on the surface of a rough…
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…
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