Mongolite is a very rare phyllosilicate mineral that typically forms as delicate, platy crystals or pseudohexagonal clusters. It is primarily found in hydrothermal veins, where it appears as small, pearly-white aggregates that are highly prized by systematic mineral collectors.
Is this mongolite?
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 mongolite with a known reference. Mongolite sits at Mohs 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: silky.
- 4Match the color rangeCompare against the expected color range: gray lilac, light violet.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: foliated, microscopic crystals.
Often confused with
Mongolite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Apophyllite is the harder of the two (Mohs 4-5 vs. 2); luster reads silky on Mongolite and vitreous to pearly on Apophyllite.
How to tell apart: Gyrolite is the harder of the two (Mohs 3-4 vs. 2); luster reads silky on Mongolite and vitreous to pearly on Gyrolite.
Often found alongside mongolite
Minerals reported to co-occur with mongolite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₄Nb₆Si₅O₂₄(OH)₁₀·6H₂O
- Mohs hardness
- 2
- Density
- 3.147 g/cm³
- Colors
- Gray lilacLight violet
- Streak
- White
- Luster
- Silky
- Transparency
- Translucent
- Crystal system
- Tetragonal
- Crystal habit
- Foliated, microscopic crystals
- Cleavage
- One direction, good
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the quartz-rich core zone of an alkalic pegmatite, as a late-stage alteration product of a niobium silicate
Where rockhounds find mongolite
Classic worldwide localities
- Dorozhny site, northern Khan-Bogdinskii granitic massif, Gobi, Mongolia
Field-hunting tip
Where it forms: In the quartz-rich core zone of an alkalic pegmatite, as a late-stage alteration product of a niobium silicate. If you start seeing polylithionite, zincian montmorillonite in float, you are in the right ground. Typical habit: foliated, microscopic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
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Find mongolite on the map
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