Telyushenkoite is a rare cesium sodium beryllium silicate that forms white to colorless equant anhedral grains. It occurs in boulders from glacial moraine. It was first described from moraine boulders, Dara-i-Pioz glacier, South Tien-Shan Mountains, Tajikistan.
Is this telyushenkoite?
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 telyushenkoite with a known reference. Telyushenkoite sits at Mohs 6, 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: white, colorless.
- 5Look at form & habitCrystal system: trigonal. Typical habit: anhedral grains, equant grains.
Often confused with
Telyushenkoite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside telyushenkoite
Minerals reported to co-occur with telyushenkoite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CsNa₆Be₂Al₃Si₁₅O₃₉F₂
- Mohs hardness
- 6
- Density
- 2.73 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Anhedral grains, equant grains
- Cleavage
- Distinct on {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In boulders from glacial moraine
Where rockhounds find telyushenkoite
Classic worldwide localities
- Moraine of the Darai-Pioz glacier in northern Tajikistan (type locality)
Field-hunting tip
Where it forms: In boulders from glacial moraine. If you start seeing reedmergnerite, microcline, pectolite in float, you are in the right ground. Typical habit: anhedral grains, equant grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify telyushenkoite?+
Where is telyushenkoite found?+
Is telyushenkoite safe to handle?+
What rocks look like telyushenkoite?+
What minerals are found with telyushenkoite?+
What kind of rock does telyushenkoite form in?+
What is telyushenkoite used for?+
Find telyushenkoite on the map
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