Wumuite is a rare potassium aluminum tungsten oxide, typically light green. It was approved as a distinct mineral species in 2018. It was first described from near Nanyang village, Panzhihua-Xichang region, on the border between Yunnan and Sichuan Provinces, China.
Is this wumuite?
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 wumuite with a known reference. Wumuite 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 to adamantine.
- 4Match the color rangeCompare against the expected color range: light green.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: platy crystals, fine-grained aggregates.
Often confused with
Wumuite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Wumuite is noticeably harder (Mohs 5-6 vs. 1-1.5); streak differs, so Wumuite leaves white, Melonite leaves dark gray; luster reads vitreous to adamantine on Wumuite and metallic on Melonite.
How to tell apart: Wumuite is noticeably harder (Mohs 5-6 vs. 3); streak differs, so Wumuite leaves white, Altaite leaves black; luster reads vitreous to adamantine on Wumuite and metallic on Altaite.
Often found alongside wumuite
Minerals reported to co-occur with wumuite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KAl₀.₃₃W₂.₆₇O₉
- Mohs hardness
- 5-6
- Density
- 6.52 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous to adamantine
- Transparency
- Transparent
- Crystal system
- Hexagonal
- Crystal habit
- Platy crystals, fine-grained aggregates
- Cleavage
- Good on {00*1} and {10*0}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In a biotite-quartz monzonite pluton near the contact zone with gabbro and nearby quartz-vein-type Au mineralization
Where rockhounds find wumuite
Classic worldwide localities
- Wumu, China
Field-hunting tip
Where it forms: In a biotite-quartz monzonite pluton near the contact zone with gabbro and nearby quartz-vein-type Au mineralization. If you start seeing tewite, scheelite, alkali feldspar in float, you are in the right ground. Typical habit: platy crystals, fine-grained aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
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Find wumuite on the map
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