Schmiederite is a rare secondary mineral found in the oxidation zones of selenium-rich hydrothermal deposits. It is most easily recognized by its distinctive dark red to orange-red color and adamantine luster, typically occurring as small tabular crystals or crusts alongside other rare selenide minerals.
Is this schmiederite?
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 schmiederite with a known reference. Schmiederite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: light blue.
- 3Read the lusterHold the specimen under a strong light. Luster: subadamantine, satiny in aggregates.
- 4Match the color rangeCompare against the expected color range: blue.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, crusts, radial aggregates.
Often confused with
Schmiederite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Schmiederite leaves light blue, Crocoite leaves yellow-orange; luster reads subadamantine, satiny in aggregates on Schmiederite and adamantine on Crocoite.
How to tell apart: Streak differs, so Schmiederite leaves light blue, Wulfenite leaves white; luster reads subadamantine, satiny in aggregates on Schmiederite and resinous, subadamantine to adamantine on Wulfenite.
Often found alongside schmiederite
Minerals reported to co-occur with schmiederite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₂Pb₂(SeO₃)(SeO₄)(OH)₄
- Mohs hardness
- 3.5
- Density
- 5.6 g/cm³
- Colors
- Streak
- Light blue
- Luster
- Subadamantine, satiny in aggregates
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular crystals, crusts, radial aggregates
- Cleavage
- Distinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral in the oxidized zone of selenium-bearing hydrothermal base metal deposits
Where rockhounds find schmiederite
Classic worldwide localities
- Tonopah-Belmont mine, Osborne district, Maricopa Co., Arizona, USA
- Cóndor mine, Los Llantenes district, Sierra de Cacheuta, La Rioja Province, Argentina
- El Dragón mine, 30 km southwest of Cerro Rico de Potosí, Potosí, Bolivia
- Llechwedd Helyg mine, Tir-y-Mynach, and at the Nantycagl (Eaglebrook) mine, Ceulanymaesmawr, Dyfed, Wales
- Dyfngwm mine, Penegoes, Powis, Wales
- Machen, Wales
Field-hunting tip
Where it forms: A rare secondary mineral in the oxidized zone of selenium-bearing hydrothermal base metal deposits. If you start seeing chalcomenite, molybdomenite, umangite in float, you are in the right ground. Typical habit: tabular crystals, crusts, radial aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify schmiederite?+
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Find schmiederite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
