Fourmarierite
Mineral Pb(UO2)4O3(OH)4·4H2O
Take care.
- Radioactive: Keep it in a closed, labelled box away from where people sit or sleep, handle it briefly, wash your hands after, and never grind or cut it.
- Contains lead: Wash your hands after handling it, keep it away from children, and don't make dust.
About it
Red to orange tabular crystals and crusts, a lead uranyl oxide formed on weathering uraninite. Named for Belgian geologist Paul Fourmarier; best known from Shinkolobwe, DR Congo.
- Type
- Mineral
- Group
- Hydroxide (uranyl oxide hydrate)
- Formula
- Pb(UO2)4O3(OH)4·4H2O
- Hardness (Mohs)
- 3–4
- Specific gravity
- 5.74–6.05
- Streak
- orange
- Lustre
- adamantine (diamond-like)
- Crystal system
- Orthorhombic
- Colours
- red, orange-red, reddish brown, brown
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect basal
Typical values: real specimens vary. For more, see mindat.org.