Cuzticite is a rare secondary mineral typically found as a yellow crust or powdery coating on oxidized tellurium ores. It is primarily identified by its distinct resinous luster and association with other rare tellurium minerals in hydrothermal systems.
Is this cuzticite?
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 cuzticite with a known reference. Cuzticite sits at Mohs 3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: yellow, brown, brownish yellow.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: encrustations, scaly, stalactitic.
Often confused with
Cuzticite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Cuzticite is noticeably harder (Mohs 3 vs. 2); streak differs, so Cuzticite leaves yellow, Tellurite leaves white; luster reads adamantine on Cuzticite and subadamantine on Tellurite.
How to tell apart: Emmonsite is the harder of the two (Mohs ~5 vs. 3); streak differs, so Cuzticite leaves yellow, Emmonsite leaves pale yellow; luster reads adamantine on Cuzticite and vitreous on Emmonsite.
Often found alongside cuzticite
Minerals reported to co-occur with cuzticite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe₂TeO₆·3H₂O
- Mohs hardness
- 3
- Density
- 3.9 g/cm³
- Streak
- Yellow
- Luster
- Adamantine
- Transparency
- Semitransparent
- Crystal system
- Hexagonal
- Crystal habit
- Encrustations, scaly, stalactitic
- Cleavage
- Good
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Very rare in oxidized ore in a matrix of intensely silicified and brecciated rhyolite vitrophyre cemented by drusy quartz and carrying pyrite and tellurides
Where rockhounds find cuzticite
Classic worldwide localities
- Moctezuma (Bambolla) mine, 12 km south of Moctezuma, Sonora, Mexico
Field-hunting tip
Where it forms: Very rare in oxidized ore in a matrix of intensely silicified and brecciated rhyolite vitrophyre cemented by drusy quartz and carrying pyrite and tellurides. If you start seeing eztlite, emmonsite, schmitterite in float, you are in the right ground. Typical habit: encrustations, scaly, stalactitic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify cuzticite?+
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Is cuzticite safe to handle?+
What rocks look like cuzticite?+
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Find cuzticite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
