Gem Identification Using Magnetism
16:53
How to Identify Gemstones & Minerals: Specific Gravity
10:02
Magnetism in Gemstones
11:46
How do you KNOW what a gem is? [Refractometer Tutorial]
12:01
Gem Tools: Refractometer
20:27
5 Simple Gem Tests Anyone Can Do | Unboxing
19:17
Rock and Mineral Identification
25:23
Amazing Inventions And Ingenious Tools That Are On Another Level
8:30