Tsepinite-Na is a rare silicate mineral belonging to the labuntsovite group, typically occurring as small, yellowish-brown prismatic crystals. It is primarily found in complex alkaline igneous environments and is highly prized by systematic mineral collectors due to its unique chemical composition and crystallography.
Is this tsepinite-na?
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-na with a known reference. Tsepinite-Na 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: colorless, white, light brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: aggregates, prismatic, radial.
Often confused with
Tsepinite-Na vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside tsepinite-na
Minerals reported to co-occur with tsepinite-na. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,H₃O,K,Sr,Ba,□)₂(Ti,Nb)₂(Si₄O₁₂)(OH,O)₂·3H₂O
- Mohs hardness
- 5
- Density
- 2.74 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Aggregates, prismatic, radial
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In cavities formed by hydrothermal alteration of alkaline pegmatite
Where rockhounds find tsepinite-na
Classic worldwide localities
- Mt. Khibinpakhchorr, Khibiny alkaline complex, and Mt. Lepkhe-Nelm, Lovozero massif, Kola Peninsula, Russia
Field-hunting tip
Where it forms: In cavities formed by hydrothermal alteration of alkaline pegmatite. If you start seeing microcline, aegirine, analcime in float, you are in the right ground. Typical habit: aggregates, prismatic, radial. Train your eye for that shape before scanning the outcrop.







