Tinaksite is a rare potassium-sodium-calcium-titanium silicate mineral highly prized for its beautiful fibrous orange-to-brown crystals. It is most famously found in association with the purple mineral charoite in the Murun Massif of Russia. Collectors should look for its distinctive acicular habit, often creating striking, radiating sprays.
Is this tinaksite?
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 tinaksite with a known reference. Tinaksite 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 on cleavages.
- 4Match the color rangeCompare against the expected color range: pink, pale yellow, light brown.
- 5Look at form & habitCrystal system: triclinic. Typical habit: fibrous, prismatic, radial.
Often confused with
Tinaksite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Tinaksite is noticeably harder (Mohs 6 vs. 4.5-5); luster reads vitreous on cleavages on Tinaksite and silky, subvitreous on Pectolite.
How to tell apart: Tinaksite is noticeably harder (Mohs 6 vs. 4.5-5).
Often found alongside tinaksite
Minerals reported to co-occur with tinaksite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₂NaCa₂TiSi₇O₁₈(OH)O
- Mohs hardness
- 6
- Density
- 2.82-2.90 g/cm³
- Streak
- White
- Luster
- Vitreous on cleavages
- Transparency
- Transparent to translucent
- Crystal system
- Triclinic
- Crystal habit
- Fibrous, prismatic, radial
- Cleavage
- Perfect on {010}, imperfect on {110}; (010) ^ (110) = 131.5°
- Rarity
- Rare
- Uses
- Collector, Lapidary
- Host rock
- An accessory mineral in potassic feldspar metasomatites at the contact with limestones (Murun massif, Russia)
Where rockhounds find tinaksite
Classic worldwide localities
- Murun massif, southwest of Olekminsk, Yakutia, and on Mt. Rasvumchorr, Khibiny massif, Kola Peninsula, Russia
Field-hunting tip
Where it forms: An accessory mineral in potassic feldspar metasomatites at the contact with limestones (Murun massif, Russia). If you start seeing potassic feldspar, aegirine, quartz in float, you are in the right ground. Typical habit: fibrous, prismatic, radial. Train your eye for that shape before scanning the outcrop.
Common questions
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Find tinaksite on the map
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