Hydrotungstite is a rare secondary tungsten mineral that typically forms as a result of the alteration of scheelite or other tungsten minerals. It is most commonly identified by its soft, yellow-to-green platy crystals that resemble mica, often found as crusts in weathered hydrothermal veins.
Is this hydrotungstite?
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 hydrotungstite with a known reference. Hydrotungstite sits at Mohs 2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Hydrotungstite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Hydrotungstite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellowish-green, green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy or micaceous aggregates, crusts.
Often confused with
Hydrotungstite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside hydrotungstite
Minerals reported to co-occur with hydrotungstite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- WO₃·2H₂O
- Mohs hardness
- 2
- Density
- 4.6 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy or Micaceous Aggregates, Crusts
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Tungsten Deposits
- Typical price
- $20-150 thumbnail
Where rockhounds find hydrotungstite
Classic worldwide localities
- Calacalani, Bolivia
- Oruro, Bolivia
- Bishop, California, USA
Field-hunting tip
Look in oxidized tungsten deposits country, the host setting where hydrotungstite typically forms. If you start seeing tungstite, scheelite, quartz in float, you are in the right ground. Field specimens usually show a platy or micaceous aggregates, crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hydrotungstite?+
Where is hydrotungstite found?+
How much is hydrotungstite worth?+
What rocks look like hydrotungstite?+
What minerals are found with hydrotungstite?+
What kind of rock does hydrotungstite form in?+
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Find hydrotungstite on the map
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