The document discusses popular gemstones, including quartz which forms amethyst and citrine and occurs in crystals, corundum which forms ruby and sapphire and is found in the USA, India, and South Africa, and beryl which forms emerald and aquamarine and produces very large crystals found in Colombia, Australia, and Russia.

1. Popular Gemstones
Mikhail Wieler

2. Introduction
 Made of Minerals
 One type of mineral can form
several types of gemstones
 Some are rare, others common
 Found worldwide
 One type of gemstone can have
several names

3. Quartz
 Occurs in crystals
 Very common mineral
 Examples: amethyst, citrine

4. Corundum
 Aluminum oxide material
 Found in USA, India, South Africa
 Examples: ruby, sapphire

5. Beryl
 Very large crystals
 Found in Colombia, Australia, Russia
 Examples: emerald, aquamarine

6. Summary
 Quartz: amethyst, citrine
 Corundum; ruby. Sapphire
 Beryl: emerald, aquamarine