Romanèchite
Romanèchite is named after its discovery locality, at Romanèche (now Romanèche-Thorins), 20 km west of Villefranche, Saône-et-Loire, France.
Romanèchite forms iron-black, dark steel-gray masses, crystals are very rare.
Romanèchite is used for ornamental purposes.
Romanèchite forms iron-black, dark steel-gray masses, crystals are very rare.
Romanèchite is used for ornamental purposes.
| General Information | ||||||||||||||||||||||||||
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| Chemical Formula |
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| Physical Properties of Romanèchite | ||||||||||||||||||||||||||
| Mohs Hardness | 5 to 6, Handbook of mineralogy (2001) | |||||||||||||||||||||||||
| Specific Gravity | 4.70 to 4.74, Handbook of mineralogy (2001) | |||||||||||||||||||||||||
| Optical Properties of Romanèchite | ||||||||||||||||||||||||||
| Optical Character | Biaxial, Handbook of mineralogy (2001) | |||||||||||||||||||||||||
| Birefringence | Strong; gray to white, Handbook of mineralogy (2001) | |||||||||||||||||||||||||
| Colour | ||||||||||||||||||||||||||
| Colour (General) | Iron-black, dark steel-gray; gray-white in reflected light., Handbook of mineralogy (2001) | |||||||||||||||||||||||||
| Transparency | Opaque, Handbook of mineralogy (2001) | |||||||||||||||||||||||||
| Lustre | Dull (Earthy),Submetallic, Handbook of mineralogy (2001) Submetallic; dull when massive | |||||||||||||||||||||||||
| Crystallography of Romanèchite | ||||||||||||||||||||||||||
| Crystal System | Monoclinic, Handbook of mineralogy (2001) | |||||||||||||||||||||||||
| Habit | Euhedral crystals very rare, flat, ridged, to 200 µm; acicular to fibrous, divergent; commonly reniform, botryoidal, stalactitic, colloform banded; very fine-grained massive., Handbook of mineralogy (2001) | |||||||||||||||||||||||||
| Geological Environment | ||||||||||||||||||||||||||
| Where found: | A product of weathering of manganese bearing oxides, carbonates, silicates; in sedimentary deposits; as replacement deposits in limestones and dolostones; a principal component of "psilomelane" and "desert varnish" (manganese oxide-rich coatings formed on rocks in arid regions); in some plume agates., Handbook of mineralogy (2001) | |||||||||||||||||||||||||
| Further Information | ||||||||||||||||||||||||||
| Mineral information: | Romanèchite information at mindat.org | |||||||||||||||||||||||||
| Significant Gem Localities | ||||||||||||||||||||||||||
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