Waimirite-(Y) is a very rare yttrium fluoride mineral discovered in Amazonian granitic pegmatites. It typically occurs as small, clear, platy crystals often found in association with other rare-element pegmatite minerals.
Is this waimirite-(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 waimirite-(y) with a known reference. Waimirite-(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. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: pink.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals.
Often confused with
Waimirite-(Y) vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside waimirite-(y)
Minerals reported to co-occur with waimirite-(y). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- YF₃
- Mohs hardness
- 5-6
- Density
- 5.586 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In veins cutting A-type granite formed by reaction with fluorine and REE-rich fluids
Where rockhounds find waimirite-(y)
Classic worldwide localities
- Pitinga mine, Presidente Figueiredo Co., Amazonas State, Brazil and at Jabal Tawlah (Mount Tawlah), Kingdom of Saudi Arabia
Field-hunting tip
Where it forms: In veins cutting A-type granite formed by reaction with fluorine and REE-rich fluids. If you start seeing biotite, albite, muscovite in float, you are in the right ground. Typical habit: platy crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify waimirite-(y)?+
Where is waimirite-(y) found?+
What rocks look like waimirite-(y)?+
What minerals are found with waimirite-(y)?+
What kind of rock does waimirite-(y) form in?+
What is waimirite-(y) used for?+
Find waimirite-(y) on the map
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