Nepskoeite is an extremely rare magnesium chloride hydroxide mineral first discovered in salt deposits in Siberia. It typically occurs as small, delicate tabular crystals in evaporate sequences alongside other saline minerals. Because of its solubility and rarity, it is almost exclusively found in professional research collections rather than private hobbyist collections.
Is this nepskoeite?
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 nepskoeite with a known reference. Nepskoeite sits at Mohs 1.5-2, 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: pearly.
- 4Match the color rangeCompare against the expected color range: yellowish white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: aggregates, fibrous, spherical.
Often confused with
Nepskoeite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside nepskoeite
Minerals reported to co-occur with nepskoeite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mg₄Cl(OH)₇·6H₂O
- Mohs hardness
- 1.5-2
- Density
- 1.76 g/cm³
- Colors
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Aggregates, fibrous, spherical
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In anhydrite-halite rock in a salt deposit
Where rockhounds find nepskoeite
Classic worldwide localities
- Nepskoye salt deposit, near Ust-Kut, Irkutsk District, Eastern Siberia, Russia
Field-hunting tip
Where it forms: In anhydrite-halite rock in a salt deposit. If you start seeing anhydrite, halite, fluoborite in float, you are in the right ground. Typical habit: aggregates, fibrous, spherical. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify nepskoeite?+
Where is nepskoeite found?+
What rocks look like nepskoeite?+
What minerals are found with nepskoeite?+
What kind of rock does nepskoeite form in?+
What is nepskoeite used for?+
Find nepskoeite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
