Mineralpedia Details for Ardennite-(As)
Ardennite-(As)
Originally just referred to as Ardennite, which was named for the type locality in the Ardennes Mountains in Belgium, it has since been redefined as Ardennite-As, as there is also a vanadate (VO4) analogue of the mineral. Ardennite-As is a rare mineral that occurs in pegmatites, quartz veins, and highly oxidized manganese and aluminum rich sediments. Localities include in, additionally, Italy, France, England, Greece, India, and Japan. Associated minerals include quartz, albite, pyrolusite, piemontite, spessartine, braunite, and hematite.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/ardennite.pdf
- Formula
- Mn2+4(AlMg)Al4(Si5As)O22(OH)6
- Crystal System
- Orthorhombic
- Crystal Habit
- Prismatic, Euhedral Crystals
- Cleavage
- Perfect, Distinct, Parting
- Luster
- Subadamantine
- Color
- yellow, yellow brown, dark brown, orange, black
- Streak
- pale brownish yellow
- Class
- Orthorhombic - Dipyramidal
- Fracture
- Brittle - Uneven
- Hardness
- 6-7
- WebMineral
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Ardennite-(As) from Arrow Junction, Central Otago, New Zealand
Orange platy crystals in what is described as "crack - seal quartz".
Ardennite-(As) from Salm-Château, Vielsalm, Stavelot Massif, Luxembourg, Belgium
Rich orange platy crystals to 5mm on Quartz.
