Yttriaite-(Y) is a rare yttrium phosphate mineral occurring primarily in granitic pegmatites. It typically forms as prismatic crystals that can be difficult to distinguish from zircon without analytical testing due to its similar appearance and potential radioactive content.
Is this yttriaite-(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 yttriaite-(y) with a known reference. Yttriaite-(Y) sits at Mohs 5.5, 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: adamantine to earthy (massive).
- 4Match the color rangeCompare against the expected color range: colorless, white.
- 5Look at form & habitCrystal system: cubic. Typical habit: prismatic crystals.
Often confused with
Yttriaite-(Y) vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Zircon is the harder of the two (Mohs 7.5 vs. 5.5); luster reads adamantine to earthy (massive) on Yttriaite-(Y) and vitreous to adamantine; greasy when metamict on Zircon.
How to tell apart: Luster reads adamantine to earthy (massive) on Yttriaite-(Y) and resinous on Monazite.
How to tell apart: Luster reads adamantine to earthy (massive) on Yttriaite-(Y) and vitreous to resinous on Xenotime-(Y).
Often found alongside yttriaite-(y)
Minerals reported to co-occur with yttriaite-(y). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Y₂O₃
- Mohs hardness
- 5.5
- Density
- 5.073 g/cm³
- Streak
- White
- Luster
- Adamantine to earthy (massive)
- Transparency
- Translucent
- Crystal system
- Cubic
- Crystal habit
- Prismatic crystals
- Cleavage
- Good on {111} [Synthetic]
- Rarity
- Rare
- Uses
- Collector, Geological study
- Host rock
- In fluvial placer sediment derived from older inter-layered sandstones, alevrites and pebbly sands
Where rockhounds find yttriaite-(y)
Classic worldwide localities
- Bol’shaya Pol’ya River, Subpolar Urals, Russia
Field-hunting tip
Where it forms: In fluvial placer sediment derived from older inter-layered sandstones, alevrites and pebbly sands. If you start seeing copper, zircon, osmium in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify yttriaite-(y)?+
Where is yttriaite-(y) found?+
Is yttriaite-(y) safe to handle?+
What rocks look like yttriaite-(y)?+
What minerals are found with yttriaite-(y)?+
What kind of rock does yttriaite-(y) form in?+
What is yttriaite-(y) used for?+
Find yttriaite-(y) on the map
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