Joesmithite is an extremely rare lead-bearing silicate mineral characterized by its complex chemical structure involving beryllium. It is primarily found in the metamorphosed iron-manganese deposits of Långban, Sweden, often appearing as dark, inconspicuous grains within a mineralized matrix. Collectors prize it as a rare mineralogical oddity rather than for its aesthetic qualities.
Is this joesmithite?
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 joesmithite with a known reference. Joesmithite sits at Mohs 5.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale brown.
- 3Read the lusterHold the specimen under a strong light. Luster: subadamantine.
- 4Match the color rangeCompare against the expected color range: black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic.
Often found alongside joesmithite
Minerals reported to co-occur with joesmithite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- PbCa₂Mg₃Fe₂(Si₆Be₂)O₂₂(OH)₂
- Mohs hardness
- 5.5
- Density
- 3.83 g/cm³
- Colors
- Streak
- Pale brown
- Luster
- Subadamantine
- Transparency
- Opaque to transparent in thin fragments
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic
- Cleavage
- Perfect on {110}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare mineral in a metamorphosed Fe{Mn orebody
Where rockhounds find joesmithite
Classic worldwide localities
- Långban, Värmland, Sweden
Field-hunting tip
Where it forms: A rare mineral in a metamorphosed Fe{Mn orebody. If you start seeing hematite, magnetite, manganoan aegirine in float, you are in the right ground. Typical habit: prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify joesmithite?+
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Find joesmithite on the map
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