Amethyst
Amethyst is the purple variety of quartz, colored by iron impurities and natural irradiation. It is the most valued quartz variety and has been prized since ancient times. In the US, Arizona's Four Peaks mine produces some of the finest amethyst in the world — a deep raspberry-purple unlike any other locality.
Physical Properties
Chemical Formula
SiO₂ (purple variety of quartz)
Hardness (Mohs)
7
Color
Purple, violet, lavender
Luster
Vitreous
Crystal System
Hexagonal (trigonal)
Streak
White
Cleavage
None
Specific Gravity
2.65
🔍 Field Identification Tips
Purple color + glassy luster + hardness 7 = amethyst. Distinguish from purple fluorite (softer, HN 4, perfect cleavage) and purple glass (no crystal form). Color is often zoned — concentrated at crystal tips.
Varieties & Forms
📍 Where to Find Amethyst in the US
Uses & Applications
Jewelry (February birthstone), crystal healing, decorative carvings, collectors specimens.
💰 Collector Value Guide
Tumbled: $2–$10. Small points: $5–$30. Quality clusters: $50–$500+. Four Peaks specimens command a premium.
Find Amethyst With Our Tools
Use the We Lick Rocks app to identify specimens, find dig sites, and connect with local rockhounds.