Zvyaginite is a rare member of the labuntsovite group found primarily in alkaline pegmatites of the Kola Peninsula. It typically forms small, clear to yellow prismatic crystals that are easily confused with other labuntsovite-group minerals due to their similar appearance and composition.
Is this zvyaginite?
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 zvyaginite with a known reference. Zvyaginite sits at Mohs 2.5-3, 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: pearly on crystal faces, greasy on breaks.
- 4Match the color rangeCompare against the expected color range: colorless, pearly-white, creamy, yellowish brown, pale pink, lilac-pink.
- 5Look at form & habitCrystal system: triclinic. Typical habit: prismatic crystals.
Often confused with
Zvyaginite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Labuntsovite is the harder of the two (Mohs 6 vs. 2.5-3); luster reads pearly on crystal faces, greasy on breaks on Zvyaginite and greasy on Labuntsovite.
How to tell apart: Nenadkevichite is the harder of the two (Mohs 5 vs. 2.5-3); luster reads pearly on crystal faces, greasy on breaks on Zvyaginite and vitreous to dull on Nenadkevichite.
Often found alongside zvyaginite
Minerals reported to co-occur with zvyaginite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na□Nb₂NaZn□Ti(Si₂O₇)₂O₂(OH)₂(H₂O)₄
- Mohs hardness
- 2.5-3
- Density
- 2.88 g/cm³
- Colors
- Streak
- White
- Luster
- Pearly on crystal faces, greasy on breaks
- Transparency
- Transparent to translucent
- Crystal system
- Triclinic
- Crystal habit
- Prismatic crystals
- Cleavage
- Perfect on {001}, two other distinct sets are nearly perpendicular to each other and to {001} under a microscope
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a hydrothermally-altered peralkaline pegmatite lens in a peripheral part of the ussingite core near its contact with the aegirine-eudialite zone; the pegmatite is part of a larger complex alkaline igneous intrusion
Where rockhounds find zvyaginite
Classic worldwide localities
- Kola Peninsula, Russia
Field-hunting tip
Where it forms: In a hydrothermally-altered peralkaline pegmatite lens in a peripheral part of the ussingite core near its contact with the aegirine-eudialite zone; the pegmatite is part of a larger complex alkaline igneous intrusion. If you start seeing microcline, sodalite, arfvedsonite in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
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Find zvyaginite on the map
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