Tewite is a rare potassium tellurium sulfate mineral found in oxidized zones of hydrothermal ore deposits. It typically forms thin, platy yellow crystals and is known primarily from the North Star mine in Utah. Collectors value it for its association with other rare tellurium-bearing secondary minerals.
Is this tewite?
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 tewite with a known reference. Tewite sits at Mohs 3.5-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: light yellow to white.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: greenish yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, tabular aggregates.
Often confused with
Tewite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Tewite is noticeably harder (Mohs 3.5-4 vs. 2); streak differs, so Tewite leaves light yellow to white, Tellurite leaves white; luster reads adamantine on Tewite and subadamantine on Tellurite.
How to tell apart: Tewite is noticeably harder (Mohs 3.5-4 vs. 1); streak differs, so Tewite leaves light yellow to white, Paratellurite leaves white; luster reads adamantine on Tewite and resinous to waxy on Paratellurite.
Often found alongside tewite
Minerals reported to co-occur with tewite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (K₁.₅□₀.₅)(Te₁.₂₅W₀.₂₅□₀.₅)₂W₅O₁₉
- Mohs hardness
- 3.5-4
- Density
- 6.903 g/cm³
- Colors
- Streak
- Light yellow to white
- Luster
- Adamantine
- Transparency
- Translucent to transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy crystals, tabular aggregates
- Cleavage
- Perfect on {100}, {001}, and {010}
- 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 tewite
Classic worldwide localities
- Near Nanyang village, Panzhihua-Xichang region, Yunnan, 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 wumuite, scheelite, alkali feldspar in float, you are in the right ground. Typical habit: platy crystals, tabular aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
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Find tewite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
