Wopmayite is a rare phosphate mineral discovered in the Tanco pegmatite in Canada, typically occurring as delicate, bladed crystal sprays. Collectors should look for its association with other phosphate species within complex pegmatite zones. It is structurally similar to fairfieldite and is often identified through analytical techniques due to its rarity and subtle macroscopic features.
Is this wopmayite?
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 wopmayite with a known reference. Wopmayite sits at Mohs 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: colorless, white, pale pink.
- 5Look at form & habitCrystal system: trigonal. Typical habit: bladed or acicular crystals forming radiating aggregates.
Often confused with
Wopmayite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Wopmayite is noticeably harder (Mohs 5 vs. 3.5); luster reads vitreous on Wopmayite and pearly to subadamantine, vitreous on the {001} cleavage on Fairfieldite.
How to tell apart: Wopmayite is noticeably harder (Mohs 5 vs. 3.5).
Often found alongside wopmayite
Minerals reported to co-occur with wopmayite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₆Na₃□Mn(PO₄)₃(PO₃OH)₄
- Mohs hardness
- 5
- Density
- 3.027 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Bladed or acicular crystals forming radiating aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary mineral in a phosphate-carbonate assemblage formed after the dissolution of primary lithiophosphate by hydrothermal solutions
Where rockhounds find wopmayite
Classic worldwide localities
- Tanco mine, Bernic Lake, Manitoba, Canada
Field-hunting tip
Where it forms: A secondary mineral in a phosphate-carbonate assemblage formed after the dissolution of primary lithiophosphate by hydrothermal solutions. If you start seeing rhodochrosite, quartz, whitlockite in float, you are in the right ground. Typical habit: bladed or acicular crystals forming radiating aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
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Find wopmayite on the map
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