Tourmaline
Tourmaline is the chameleon of minerals — no other mineral species produces such a complete spectrum of colors in gem quality. Maine's Oxford County is legendary for producing multicolored elbaite tourmaline in watermelon, raspberry, and minty green tones. California's Pala and Mesa Grande districts have produced some of the world's finest rubellite and bicolored gems.
Physical Properties
Chemical Formula
Complex boron silicate group
Hardness (Mohs)
7–7.5
Color
Every color — often multicolored in same crystal
Luster
Vitreous
Crystal System
Hexagonal (trigonal)
Streak
White
Cleavage
Very poor
Specific Gravity
3.0–3.25
🔍 Field Identification Tips
Triangular cross-section with rounded corners is diagnostic. Striated parallel to crystal length. No cleavage. Hardness 7–7.5. Found in granitic pegmatites alongside lepidolite, cleavelandite, and quartz.
Varieties & Forms
📍 Where to Find Tourmaline in the US
Uses & Applications
Jewelry (October birthstone along with opal), piezoelectric devices, pressure gauges, gemstones.
💰 Collector Value Guide
Black schorl: $1–$5. Colored gem rough: $10–$200/ct. Maine rubellite: $100–$1,000/ct. Paraíba (neon blue-green): $10,000+/ct.
Find Tourmaline With Our Tools
Use the We Lick Rocks app to identify specimens, find dig sites, and connect with local rockhounds.