Thorite
Mineral (Th,U)SiO4
Also called Orangite and Uranothorite
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.
About it
Black to orange thorium silicate, usually glassy and metamict from its own radiation, in pegmatites and syenite; Bancroft, Ontario, and Norway's Langesund fjord. Strongly radioactive.
- Type
- Mineral
- Group
- Silicate (nesosilicate), zircon group
- Formula
- (Th,U)SiO4
- Hardness (Mohs)
- 4.5–5
- Specific gravity
- 4–7.2
- Streak
- light orange to brown
- Lustre
- vitreous (glassy), resinous, greasy
- Crystal system
- Tetragonal
- Colours
- black, brownish black, orange, yellow-orange
- Transparency
- transparent, translucent, opaque
- Cleavage and fracture
- distinct prismatic; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.