Answer:
1. PYRITE- Also known as fools gold, it is used as an ornamental material.
2. OLIVINE-The gem quality variety is known as peridot.
3. GARNET- A common mineral, but rarely having gem quality or color.
4. CORUNDUM-The gem quality grade of corundum is sapphire.
5. AMAZONITE- A rare green form of microcline feldspar.
6. SPODUMENE- A lithium aluminum silicate. Kunzite is the gem variety.
7. TURQUOISE-A copper mineral that has been used as a gem by America Indians for centuries.
8. AGATE-A banded form of quartz used for carvings and ornamental stones.
9. SNOWFLAKE OBSIDIAN-A form of volcanic glass, the snowflakes are inclusions of the mineral cristobalite.
10. TOURMALINE-Black tourmaline is commonly found in pegmatites. Gem tourmaline is usually green, pink or blue.
11. JADEITE - The gem quality is used in sculptures and costume jewelry.
12. AMETHYST-A purple variety of quartz used in jewelry.
13. RHODONITE-A magnesium silicate mineral used in jewelry and carvings.
14. QUARTZ CRYSTAL- Collectors of quartz crystals first believed that quartz crystals, or rock crystals were petrified ice.
15. BERYL-A beryllium aluminum silicate, aquamarine and emerald are gem varieties of this mineral.