Gowerite is a rare calcium borate mineral that typically forms as delicate, radial aggregates or bladed crystals. It is primarily identified within borate-rich sedimentary deposits and is a prized find for advanced mineral collectors focusing on evaporite species.
Is this gowerite?
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 gowerite with a known reference. Gowerite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Gowerite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Gowerite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: bladed crystals, radial aggregates, spherulitic.
Often confused with
Gowerite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside gowerite
Minerals reported to co-occur with gowerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaB₆O₁₀·3H₂O
- Mohs hardness
- 3
- Density
- 2.28 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Bladed Crystals, Radial Aggregates, Spherulitic
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Borate Deposits in Sedimentary Basins
- Typical price
- $20-100 per specimen
Where rockhounds find gowerite
Classic worldwide localities
- Death Valley, California, USA
- Boron, California, USA
Field-hunting tip
Look in borate deposits in sedimentary basins country — that is the host setting where gowerite typically forms. If you start seeing colemanite, ulexite, howlite in float, you are in the right ground. Field specimens usually show a bladed crystals, radial aggregates, spherulitic habit, so train your eye for that shape before scanning the outcrop.




