Zincostaurolite is a rare zinc-dominant member of the staurolite group. It is found in metamorphic environments and is visually nearly indistinguishable from common staurolite without chemical analysis.
Is this zincostaurolite?
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 zincostaurolite with a known reference. Zincostaurolite sits at Mohs 7-7.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Zincostaurolite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Zincostaurolite typically shows a subvitreous luster.
- 4Match the color rangeCompare against the expected color range: dark brown, reddish brown, yellowish brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals.
Often confused with
Zincostaurolite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside zincostaurolite
Minerals reported to co-occur with zincostaurolite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Zn₂Al₉O₆(SiO₄)₄(O,OH)₂
- Mohs hardness
- 7-7.5
- Density
- 3.7-3.8 g/cm³
- Streak
- White
- Luster
- Subvitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals
- Cleavage
- Distinct On {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphic Rocks
- Typical price
- $20-200 per specimen
Where rockhounds find zincostaurolite
Classic worldwide localities
- Finland
- France
- Italy
Field-hunting tip
Look in metamorphic rocks country, the host setting where zincostaurolite typically forms. If you start seeing kyanite, garnet, mica in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify zincostaurolite?+
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How much is zincostaurolite worth?+
What rocks look like zincostaurolite?+
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Find zincostaurolite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
