Chromschieffelinite is an extremely rare lead tellurite chromate mineral occurring as minute tabular crystals or crusts. It is found exclusively in oxidized tellurium-rich zones of base metal deposits, specifically noted at the Grand Central mine in Tombstone. Collectors primarily seek it as an aesthetic and scientific curiosity due to its limited distribution and complex mineral chemistry.
Is this chromschieffelinite?
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 chromschieffelinite with a known reference. Chromschieffelinite 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. Streak: pale yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: pale yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: tabular crystals, crusts, or radiating sprays.
Often confused with
Chromschieffelinite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Chromschieffelinite leaves pale yellow, Schieffelinite leaves white.
How to tell apart: Emmonsite is the harder of the two (Mohs ~5 vs. 2); luster reads adamantine on Chromschieffelinite and vitreous on Emmonsite.
How to tell apart: Tlapallite is the harder of the two (Mohs 3 vs. 2); luster reads adamantine on Chromschieffelinite and vitreous on Tlapallite.
Often found alongside chromschieffelinite
Minerals reported to co-occur with chromschieffelinite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₁₀Te₆O₂₀(OH)₁₄(CrO₄)·5H₂O
- Mohs hardness
- 2
- Density
- 5.892 g/cm³
- Colors
- Streak
- Pale yellow
- Luster
- Adamantine
- Transparency
- Transparent to translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Tabular crystals, crusts, or radiating sprays
- Cleavage
- Perfect on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary mineral in the oxidized zone of a telluride and galena deposit
Where rockhounds find chromschieffelinite
Classic worldwide localities
- Bird Nest drift, southwest flank of Otto Mountain, 0.4 miles northwest of the Aga mine, near Baker, California, USA
Field-hunting tip
Where it forms: A secondary mineral in the oxidized zone of a telluride and galena deposit. If you start seeing chalcopyrite, chrysocolla, galena in float, you are in the right ground. Typical habit: tabular crystals, crusts, or radiating sprays. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify chromschieffelinite?+
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Is chromschieffelinite safe to handle?+
What rocks look like chromschieffelinite?+
What minerals are found with chromschieffelinite?+
What kind of rock does chromschieffelinite form in?+
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Find chromschieffelinite on the map
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