Kainosite-(Y) is a rare yttrium-calcium silicate that typically forms as translucent, prismatic orthorhombic crystals. It is highly prized by micromounters and advanced collectors for its distinct bright yellow fluorescence under short-wave ultraviolet light, often found in alkaline pegmatites or associated with hydrothermal alteration.
Is this kainosite-(y)?
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 kainosite-(y) with a known reference. Kainosite-(Y) sits at Mohs 5-6 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Kainosite-(Y) leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Kainosite-(Y) typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellowish-brown, brown, colorless.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: prismatic crystals, radial aggregates.
Often confused with
Kainosite-(Y) vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Luster reads vitreous on Kainosite-(Y) and adamantine on Titanite.
How to tell apart: Zircon is the harder of the two (Mohs 7.5 vs. 5-6); luster reads vitreous on Kainosite-(Y) and adamantine on Zircon.
Often found alongside kainosite-(y)
Minerals reported to co-occur with kainosite-(y). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂(Y,REE)₂Si₄O₁₂CO₃·H₂O
- Mohs hardness
- 5-6
- Density
- 3.39-3.41 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Prismatic Crystals, Radial Aggregates
- Cleavage
- Distinct On {110}
- Fluorescence
- Bright Yellow Under SW UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alkaline Pegmatites and Hydrothermal Veins
- Typical price
- $50-300 per specimen depending on crystal size and quality
Where rockhounds find kainosite-(y)
Classic worldwide localities
- Hittero, Norway
- Kola Peninsula, Russia
- Mont Saint-Hilaire, Canada
- Langesundsfjord, Norway
Field-hunting tip
Look in alkaline pegmatites and hydrothermal veins country — that is the host setting where kainosite-(y) typically forms. If you start seeing quartz, microcline, fluorite in float, you are in the right ground. Field specimens usually show a prismatic crystals, radial aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify kainosite-(y)?+
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How much is kainosite-(y) worth?+
Is kainosite-(y) safe to handle?+
What rocks look like kainosite-(y)?+
What minerals are found with kainosite-(y)?+
What kind of rock does kainosite-(y) form in?+
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Find kainosite-(y) on the map
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