Thalénite-(Y) is a rare yttrium silicate mineral that typically forms in granite pegmatites. Collectors generally look for its distinctive pink or flesh-red tabular crystals often associated with other rare earth minerals.
Is this thalénite-(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 thalénite-(y) with a known reference. Thalénite-(Y) sits at Mohs 6.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Thalénite-(Y) leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Thalénite-(Y) typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: pink, flesh-red, gray, brownish, colorless.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, massive, granular.
Often confused with
Thalénite-(Y) vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside thalénite-(y)
Minerals reported to co-occur with thalénite-(y). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Y₃Si₃O₁₀(OH)
- Mohs hardness
- 6.5
- Density
- 4.2-4.3 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Massive, Granular
- Cleavage
- Distinct On {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
- Typical price
- $50-300 per specimen depending on quality
Where rockhounds find thalénite-(y)
Classic worldwide localities
- Österby, Dalarna, Sweden
- Evje, Norway
- Hittero, Norway
- Madagascar
- Colorado, USA
Field-hunting tip
Look in granite pegmatites country — that is the host setting where thalénite-(y) typically forms. If you start seeing fluocerite, gadolinite, yttrialite in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify thalénite-(y)?+
Where is thalénite-(y) found?+
How much is thalénite-(y) worth?+
Is thalénite-(y) safe to handle?+
What rocks look like thalénite-(y)?+
What minerals are found with thalénite-(y)?+
What kind of rock does thalénite-(y) form in?+
What is thalénite-(y) used for?+
Find thalénite-(y) on the map
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