Jamesite is a rare lead zinc iron arsenate, typically red-brown. It is a secondary mineral in oxidized lead ore in a dolostone-hosted hydrothermal polymetallic ore deposit. Associated minerals include duftite, tsumcorite and goethite. It was first described from Tsumeb, Namibia.
Is this jamesite?
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 jamesite with a known reference. Jamesite 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: pale brown.
- 3Read the lusterHold the specimen under a strong light. Luster: subadamantine.
- 4Match the color rangeCompare against the expected color range: reddish brown.
- 5Look at form & habitCrystal system: triclinic. Typical habit: acicular crystals, radiated aggregates, crusts.
Often confused with
Jamesite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Duftite is the harder of the two (Mohs 4.5 vs. ~3); luster reads subadamantine on Jamesite and dull to vitreous on fractures on Duftite.
How to tell apart: Streak differs, so Jamesite leaves pale brown, Mimetite leaves white; luster reads subadamantine on Jamesite and resinous to subadamantine on Mimetite.
Often found alongside jamesite
Minerals reported to co-occur with jamesite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₂ZnFe³⁺₂(Fe³⁺,Zn)₄(AsO₄)₄(OH)₈(OH,O)₂
- Mohs hardness
- ~3
- Density
- 5.1 g/cm³
- Colors
- Streak
- Pale brown
- Luster
- Subadamantine
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Acicular crystals, radiated aggregates, crusts
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary mineral in oxidized lead ore in a dolostone-hosted hydrothermal polymetallic ore deposit
Where rockhounds find jamesite
Classic worldwide localities
- Tsumeb, Namibia
Field-hunting tip
Where it forms: A secondary mineral in oxidized lead ore in a dolostone-hosted hydrothermal polymetallic ore deposit. If you start seeing duftite, tsumcorite, goethite in float, you are in the right ground. Typical habit: acicular crystals, radiated aggregates, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify jamesite?+
Where is jamesite found?+
Is jamesite safe to handle?+
What rocks look like jamesite?+
What minerals are found with jamesite?+
What kind of rock does jamesite form in?+
What is jamesite used for?+
Find jamesite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
