Plumbotsumite is a rare lead silicate mineral known primarily from the Tsumeb Mine in Namibia. It typically appears as thin, pearly white plates or delicate radiating clusters occurring as late-stage secondary minerals in oxidized ore zones.
Is this plumbotsumite?
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 plumbotsumite with a known reference. Plumbotsumite 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: white.
- 3Read the lusterHold the specimen under a strong light. Luster: resinous to adamantine; pearly on cleavage surfaces.
- 4Match the color rangeCompare against the expected color range: colorless.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, radial aggregates, crusts.
Often confused with
Plumbotsumite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads resinous to adamantine; pearly on cleavage surfaces on Plumbotsumite and dull to adamantine on Plumboselite.
How to tell apart: Cerussite is the harder of the two (Mohs 3-3.5 vs. ~2); luster reads resinous to adamantine; pearly on cleavage surfaces on Plumbotsumite and adamantine, tending toward vitreous, resinous on Cerussite.
Often found alongside plumbotsumite
Minerals reported to co-occur with plumbotsumite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₅Si₄O₈(OH)₁₀
- Mohs hardness
- ~2
- Density
- 5.6 g/cm³
- Colors
- Streak
- White
- Luster
- Resinous to adamantine; pearly on cleavage surfaces
- Transparency
- Transparent to translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy crystals, radial aggregates, crusts
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary mineral developed in the oxidized zone above complex galena-bearing ores
Where rockhounds find plumbotsumite
Classic worldwide localities
- Mammoth-St. Anthony mine, Tiger, Pinal Co., Arizona, USA
- Tsumeb, Namibia
Field-hunting tip
Where it forms: A secondary mineral developed in the oxidized zone above complex galena-bearing ores. If you start seeing alamosite, melanotekite, wulfenite in float, you are in the right ground. Typical habit: platy crystals, radial aggregates, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify plumbotsumite?+
Where is plumbotsumite found?+
Is plumbotsumite safe to handle?+
What rocks look like plumbotsumite?+
What minerals are found with plumbotsumite?+
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Find plumbotsumite on the map
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