Lópezite
Lopezite | |
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General | |
Category | Sulfate minerals (chromate) |
Formula (repeating unit) | K2Cr2O7 |
Strunz classification | 7.FD.05 |
Dana classification | 35.2.1.1 Anhydrous chromates |
Crystal system | Triclinic |
Crystal class | Pinacoidal (1) (same H-M symbol) |
Space group | P1 |
Identification | |
Color | Orange-red, red |
Crystal habit | Granular or spherical in small crystals on the natural environment. Prismatic on lab grown crystals. |
Cleavage | Perfect [010] perfect, [100] distinct, [001] distinct |
Mohs scale hardness | 2+1⁄2 |
Luster | Vitreous |
Streak | Light yellow |
Diaphaneity | Transparent |
Specific gravity | 2.69 |
Pleochroism | Visible |
Solubility | soluble in water |
Other characteristics | Health risks: contains the carcinogenic and mutagenic chromate ion. |
References | [1][2] |
Lopezite is a rare red chromate mineral with chemical formula: K2Cr2O7. It crystallizes in the triclinic crystal system.[1][2]
It occurs as rare vug fillings in nitrate ores in association with tarapacáite (K2CrO4), and ulexite in the Chilean Atacama and is reported from the Bushveld igneous complex of South Africa.[1][2] Lopezite was first described in 1937 for an occurrence in Iquique Province, Chile and named after Chilean mining engineer Emiliano López Saa (1871–1959).[1]
Most lopezite offered for sale to collectors is artificially produced.[1] Synthetic varieties also exhibit monoclinic crystals.[3]
References[]
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Categories:
- Potassium minerals
- Chromate minerals
- Triclinic minerals
- Minerals in space group 2
- Oxide mineral stubs
- Oxide minerals