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 4-5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Jamesite leaves a pale brown streak.
- 3Read the lusterHold the specimen under a strong light. Jamesite typically shows a subadamantine luster.
- 4Match the color rangeCompare against the expected color range: red-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: Streak differs, so Jamesite leaves pale brown, Duftite leaves light green; luster reads subadamantine on Jamesite and vitreous 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
- 4-5
- Density
- 5.084 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
- Oxidized Zones of Hydrothermal Polymetallic Ore Deposits
Where rockhounds find jamesite
Classic worldwide localities
- Tsumeb Mine, Namibia
Field-hunting tip
Look in oxidized zones of hydrothermal polymetallic ore deposits country, the host setting where jamesite typically forms. If you start seeing duftite, tennantite, galena in float, you are in the right ground. Field specimens usually show a acicular crystals, radiated aggregates, crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find jamesite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
