Thorikosite is a very rare lead oxychloride mineral primarily found in ancient lead-smelting slags at Laurium, Greece. It typically forms thin, yellowish, plate-like crystals associated with other rare lead-bearing species in slag cavities.
Is this thorikosite?
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 thorikosite with a known reference. Thorikosite sits at Mohs 3, 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: vitreous.
- 4Match the color rangeCompare against the expected color range: light yellow.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: prismatic.
Often confused with
Thorikosite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside thorikosite
Minerals reported to co-occur with thorikosite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₃O₃Sb(OH)Cl₂
- Mohs hardness
- 3
- Density
- 7.24 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Tetragonal
- Crystal habit
- Prismatic
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral formed through alteration of lead-bearing slag by sea water
Where rockhounds find thorikosite
Classic worldwide localities
- Laurium, Greece, in slag
Field-hunting tip
Where it forms: A rare secondary mineral formed through alteration of lead-bearing slag by sea water. If you start seeing paralaurionite, laurionite, hydrocerussite 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 thorikosite?+
Where is thorikosite found?+
Is thorikosite safe to handle?+
What rocks look like thorikosite?+
What minerals are found with thorikosite?+
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What is thorikosite used for?+
Find thorikosite on the map
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