Tienshanite is a rare borosilicate mineral typically found in complex alkaline pegmatites. It is prized by advanced collectors for its specific crystal habits and unique composition, usually occurring as small, transparent to translucent yellowish-brown grains or short prismatic crystals.
Is this tienshanite?
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 tienshanite with a known reference. Tienshanite sits at Mohs 6-6.5, 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: vitreous.
- 4Match the color rangeCompare against the expected color range: pistachio green.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: prismatic to tabular crystals.
Often confused with
Tienshanite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Tienshanite is noticeably harder (Mohs 6-6.5 vs. 2-3); streak differs, so Tienshanite leaves white, Barytolamprophyllite leaves light brown.
How to tell apart: Tienshanite is noticeably harder (Mohs 6-6.5 vs. ~5).
Often found alongside tienshanite
Minerals reported to co-occur with tienshanite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K(Na,K,□)₉Ca₂Ba₆Mn₆Ti₆B₁₂Si₃₆O₁₁₄(O,OH,F)₁₁
- Mohs hardness
- 6-6.5
- Density
- 3.29 g/cm³
- Colors
- Pistachio green
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Hexagonal
- Crystal habit
- Prismatic to tabular crystals
- Cleavage
- {001}, distinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the central portions of alkalic pegmatites in syenite
Where rockhounds find tienshanite
Classic worldwide localities
- Dara-i-Pioz massif, Alai Range, Tien Shan, Tajikistan
Field-hunting tip
Where it forms: In the central portions of alkalic pegmatites in syenite. If you start seeing pyrochlore, astrophyllite, bafertisite in float, you are in the right ground. Typical habit: prismatic to tabular crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify tienshanite?+
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What rocks look like tienshanite?+
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Find tienshanite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
