Karpinskite is a rare magnesium nickel silicate. It occurs in veinlets in "kerolitized" serpentinite. It was first described from Nizhni Tagil massif, Ural Mountains, Russia.
Is this karpinskite?
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 karpinskite with a known reference. Karpinskite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Karpinskite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Karpinskite typically shows a dull to greasy luster.
- 4Match the color rangeCompare against the expected color range: colorless, light blue, deep greenish blue.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: fibrous aggregates, acicular crystals.
Often confused with
Karpinskite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Wurtzite is the harder of the two (Mohs 3.5-4 vs. 2.5); streak differs, so Karpinskite leaves white, Wurtzite leaves brownish-yellow to light brown; luster reads dull to greasy on Karpinskite and resinous on Wurtzite.
How to tell apart: Sphalerite is the harder of the two (Mohs 3.5-4 vs. 2.5); streak differs, so Karpinskite leaves white, Sphalerite leaves white to yellow-brown; luster reads dull to greasy on Karpinskite and resinous to submetallic on Sphalerite.
Often found alongside karpinskite
Minerals reported to co-occur with karpinskite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Mg,Ni)₂Si₂O₅(OH)₂
- Mohs hardness
- 2.5
- Density
- 2.53 g/cm³
- Streak
- White
- Luster
- Dull to Greasy
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Fibrous Aggregates, Acicular Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alkaline Pegmatites
Where rockhounds find karpinskite
Classic worldwide localities
- Kola Peninsula, Russia
Field-hunting tip
Look in alkaline pegmatites country, the host setting where karpinskite typically forms. If you start seeing albite, aegirine, chlorite in float, you are in the right ground. Field specimens usually show a fibrous aggregates, acicular crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find karpinskite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
