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…
Clarity Grading Diamonds
Step 4: Gem Grading Lesson 12 Back to syllabus When clarity grading a diamond, gemologists examine anything that interferes with the free passage…
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…
Traditional Diamond Cut Grading Methods
Of the Four Cs of gem grading, cut ranks as the most important for diamonds. The cut (or make) determines why one diamond features spectacular fountains…
Appraising Opals
Step 4: Gem Grading Lesson 17 Back to syllabus Gemologists can determine the color, clarity, and cut grades of gems like diamonds and rubies reasonably…
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…
Destructive Gemstone Tests: Hot Point Testing
Hot point testing can determine if some gem materials are plastic imitations. It can also reveal if a stone is treated with wax or plastic. By Donald…
Destructive Gemstone Tests: Dye Testing
Gems are frequently dyed to enhance their color. Distinguishing natural from enhanced stones is an essential skill for gemologists. The materials…
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