Tsepinite-Ca is a rare member of the labuntsovite group, typically occurring as small, elongated prismatic crystals in alkaline igneous environments. Collectors prize it for its specific chemical composition and occurrence within the complex mineral assemblages of the Khibiny alkaline massif.
Is this tsepinite-ca?
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 tsepinite-ca with a known reference. Tsepinite-Ca sits at Mohs 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: white, pale brownish white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular, prismatic, wheat sheaf.
Often confused with
Tsepinite-Ca vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside tsepinite-ca
Minerals reported to co-occur with tsepinite-ca. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Ca,Na,K,◻)₄(Ti,Nb)₄(Si₄O₁₂)₂(OH,O)₄·5H₂O
- Mohs hardness
- 5
- Density
- 2.73 g/cm³
- Colors
- WhitePale brownish white
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular, prismatic, wheat sheaf
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In cavities formed by hydrothermal leaching of rinkite in a pegmatite that cuts nepheline syenite
Where rockhounds find tsepinite-ca
Classic worldwide localities
- Lovchorrite mine, HackmanValley, Mount Yukspor, Khibiny alkaline massif, Kola Peninsula, Russia
Field-hunting tip
Where it forms: In cavities formed by hydrothermal leaching of rinkite in a pegmatite that cuts nepheline syenite. If you start seeing microcline, aegirine, natrolite in float, you are in the right ground. Typical habit: acicular, prismatic, wheat sheaf. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify tsepinite-ca?+
Where is tsepinite-ca found?+
What rocks look like tsepinite-ca?+
What minerals are found with tsepinite-ca?+
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What is tsepinite-ca used for?+
Find tsepinite-ca on the map
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