Ganterite is a rare barium-rich mica typically found in high-grade metamorphic rocks. It forms thin, platy, micaceous crystals that are visually indistinguishable from muscovite without analytical testing.
Is this ganterite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch ganterite with a known reference. Ganterite sits at Mohs 4-4.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: light gray, silver.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: micaceous.
Often confused with
Ganterite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside ganterite
Minerals reported to co-occur with ganterite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ba₀.₅(Na,K)₀.₅Al₂(Si₂.₅Al₁.₅)O₁₀(OH)₂
- Mohs hardness
- 4-4.5
- Density
- 3.11 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent to transparent
- Crystal system
- Monoclinic
- Crystal habit
- Micaceous
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rock forming mineral in bands and lenses of white-mica schists and in zoisite– celsian gneiss
Where rockhounds find ganterite
Classic worldwide localities
- Lincoln Hill, near Oreana, Nevada, USA
- Berisal complex, Wasenhorn, Simplon region, Switzerland
Field-hunting tip
Where it forms: A rock forming mineral in bands and lenses of white-mica schists and in zoisite– celsian gneiss. If you start seeing muscovite, zoisite, quartz in float, you are in the right ground. Typical habit: micaceous. Train your eye for that shape before scanning the outcrop.







