Chrome chalcedony
| Chrome chalcedony | |
|---|---|
Zimbabwean chrome chalcedony (known locally as mtorolite). Scale is in centimetres. | |
| General | |
| Category | Tectosilicate minerals |
| Group | Quartz group |
| Formula | Silica (SiO2) |
| IMA status | Variety of quartz (chalcedony) |
| Crystal system | Trigonal (quartz), monoclinic (moganite) |
| Identification | |
| Formula mass | 60 g/mol |
| Color | Emerald green |
| Cleavage | Absent |
| Fracture | Uneven, splintery, conchoidal |
| Mohs scale hardness | 6–7 |
| Luster | Vitreous, dull, greasy, silky |
| Streak | White |
| Diaphaneity | Translucent |
| Specific gravity | Usually 2.60, sometimes greater than 2.62 |
Chrome chalcedony is a green variety of the mineral chalcedony, colored by small quantities of chromium. Its name is derived from Mutorashanga, a small ferrochrome mining town in Zimbabwe where the mineral was discovered in the 1950s.
It is most commonly found in Zimbabwe, where it is known as Mtorolite, Mtorodite, or Matorolite. It is also marketed using the trade name, Aquaprase.