Garnet
Garnet is a group of closely related silicate minerals that share the same crystal structure but vary in chemical composition. Most famously known in dark red, garnets actually come in every color except blue. Idaho produces the rare star garnet — one of only two places in the world (the other is India) where asterism is seen in garnet.
Physical Properties
Chemical Formula
Various silicates (complex group)
Hardness (Mohs)
6.5–7.5
Color
Red (most common), orange, yellow, green, purple, black
Luster
Vitreous to resinous
Crystal System
Cubic (isometric)
Streak
White
Cleavage
Dodecahedral (imperfect)
Specific Gravity
3.5–4.3
🔍 Field Identification Tips
Dodecahedral or trapezohedral crystal habit (12 or 24 faces) is distinctive. Look for dark red crystals embedded in schist and gneiss. Hardness 6.5–7.5. No cleavage. Often found in metamorphic rocks along with mica.
Varieties & Forms
📍 Where to Find Garnet in the US
Uses & Applications
Jewelry (January birthstone), abrasive (garnet paper), waterjet cutting abrasive, gemstones.
💰 Collector Value Guide
Common red garnet rough: $5–$20/lb. Quality rhodolite: $50–$500/ct cut. Idaho star garnets: $50–$500/stone. Demantoid garnets: $1,000+/ct.
Find Garnet With Our Tools
Use the We Lick Rocks app to identify specimens, find dig sites, and connect with local rockhounds.