Yttrialite-(Y) is a rare yttrium-thorium silicate mineral typically found in granite pegmatites. It is often metamict due to radiation damage, meaning its internal crystal structure is partially destroyed, resulting in an amorphous appearance that is frequently found associated with other rare-earth minerals.
Is this yttrialite-(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 yttrialite-(y) with a known reference. Yttrialite-(Y) sits at Mohs 5-5.5, 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: vitreous.
- 4Match the color rangeCompare against the expected color range: green, orangish yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: massive.
Often confused with
Yttrialite-(Y) vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside yttrialite-(y)
Minerals reported to co-occur with yttrialite-(y). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Y₂Si₂O₇
- Mohs hardness
- 5-5.5
- Density
- 4.58 g/cm³
- Colors
- GreenOrangish yellow
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A late-stage mineral in some rare-earth-bearing pegmatites
Where rockhounds find yttrialite-(y)
Classic worldwide localities
- Baringer Hill pegmatite, 26 km west of Burnet, and from Rode Ranch, near Blu®ton, Llano County, Texas, USA (type locality)
Field-hunting tip
Where it forms: A late-stage mineral in some rare-earth-bearing pegmatites. If you start seeing gadolinite, fergusonite, thorite in float, you are in the right ground. Typical habit: massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify yttrialite-(y)?+
Where is yttrialite-(y) found?+
Is yttrialite-(y) safe to handle?+
What rocks look like yttrialite-(y)?+
What minerals are found with yttrialite-(y)?+
What kind of rock does yttrialite-(y) form in?+
What is yttrialite-(y) used for?+
Find yttrialite-(y) on the map
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