Mroseite is a very rare tellurite mineral discovered in the oxidized zones of the Moctezuma mine in Mexico. It typically forms small, clear, tabular or platy crystals that are highly sought after by advanced collectors of rare minerals.
Is this mroseite?
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 mroseite with a known reference. Mroseite sits at Mohs ~4, 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: adamantine.
- 4Match the color rangeCompare against the expected color range: colorless, white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, tabular aggregates.
Often confused with
Mroseite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Mroseite is noticeably harder (Mohs ~4 vs. 2); luster reads adamantine on Mroseite and subadamantine on Tellurite.
How to tell apart: Mroseite is noticeably harder (Mohs ~4 vs. 1); luster reads adamantine on Mroseite and resinous to waxy on Paratellurite.
Often found alongside mroseite
Minerals reported to co-occur with mroseite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaTeO₂(CO₃)
- Mohs hardness
- ~4
- Density
- 4.35 g/cm³
- Streak
- White
- Luster
- Adamantine
- Transparency
- Semitransparent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy crystals, tabular aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Very rare in a hydrothermal Au–Te deposit (Moctezuma mine, Mexico)
Where rockhounds find mroseite
Classic worldwide localities
- Tombstone Exploration open pit, Tombstone, Cochise Co., Arizona, USA
- Moctezuma (Bambolla) mine, 12 km south of Moctezuma, Sonora, Mexico
Field-hunting tip
Where it forms: Very rare in a hydrothermal Au–Te deposit (Moctezuma mine, Mexico). If you start seeing spiroffite, tellurium, tellurite 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
How do you identify mroseite?+
Where is mroseite found?+
Is mroseite safe to handle?+
What rocks look like mroseite?+
What minerals are found with mroseite?+
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Find mroseite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
