Tengerite-(Y) is a rare yttrium carbonate mineral typically found as an alteration product of other rare-earth minerals like gadolinite. It most commonly appears as white to yellowish-white earthy crusts or delicate platy aggregates in granitic pegmatites. Collectors look for it as a secondary coating on matrix rocks associated with pegmatite minerals.
Is this tengerite-(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 tengerite-(y) with a known reference. Tengerite-(Y) sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Tengerite-(Y) leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Tengerite-(Y) typically shows a dull luster.
- 4Match the color rangeCompare against the expected color range: white, yellowish-white, colorless.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, crusts, radial aggregates.
Often confused with
Tengerite-(Y) vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside tengerite-(y)
Minerals reported to co-occur with tengerite-(y). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Y₂(CO₃)₃·nH₂O
- Mohs hardness
- 3.5
- Density
- 3.3 g/cm³
- Streak
- White
- Luster
- Dull
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Platy Crystals, Crusts, Radial Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
- Typical price
- $50-300 per specimen
Where rockhounds find tengerite-(y)
Classic worldwide localities
- Iveland, Norway
- Ytterby, Sweden
- Kola Peninsula, Russia
- Bancroft, Ontario, Canada
Field-hunting tip
Look in granite pegmatites country — that is the host setting where tengerite-(y) typically forms. If you start seeing gadolinite, fluorite, apatite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts, radial aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify tengerite-(y)?+
Where is tengerite-(y) found?+
How much is tengerite-(y) worth?+
What rocks look like tengerite-(y)?+
What minerals are found with tengerite-(y)?+
What kind of rock does tengerite-(y) form in?+
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Find tengerite-(y) on the map
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