Lesson 4: Gemology Cheat Sheets
Step 3: Practical Gemology
Use these gemology cheat sheets to review color and clarity grading, as well as special information on diamonds and opals. You can also review basic gem identification testing procedures for the refractometer, polariscope, and specific gravity.
Each section contains links to International Gem Society (IGS) articles that discuss these topics in greater detail.
Evaluating Colored Gemstone Clarity
The Gemological Institute of America (GIA) has devised a clarity grading system that, first, groups colored gemstones into three types:
GIA Clarity Types
Usually eye clean
Almost always included
Chrysoberyl, yellow and green
Every Gemstone Is Unique - Here's How The Experts Evaluate Them
in this training-course, discover the tools, tests & valuation process used by expert gemologists for colored gemstones, opals & diamonds