THE MINERAL META-VARISCITE
- Chemistry: AlPO4 - 2H2O, Hydrated Aluminum Phosphate
- Class: Phosphates
- Uses: Only as mineral specimens.
Metavariscite is a rare phosphate mineral that is rather difficult to distinguish from its very close cousin, variscite
The two minerals are polymorphs
, meaning many shapes, since the two minerals have the same chemistry but different atomic structures.
Variscite is orthorhombic and metavariscite is monoclinic.
Despite this difference the two are not easily distinguished as they rarely form even tiny crystals which might show their true symmetries.
Both minerals form mostly crusts and nodules that are usually green.
Metavariscite is almost always a pale green while variscite's color is somewhat more variable and when green is usually darker.
- Color is light green.
- Luster is vitreous or waxy.
- Transparency: Specimens are translucent to opaque.
- Crystal System is monoclinic; 2/m
- Crystal Habits include nodules, fine grain masses, and crusts.
- Cleavage is not seen.
- Fracture is conchoidal, splintery, uneven.
- Hardness is variable from 3.5
- Specific Gravity is approximately 2.53 (average)
- Streak is white.
- Associated Minerals are limonite, chalcedony, crandallite, variscite, wardite and other secondary phosphate minerals.
- Notable Occurrence includes Edison-Bird Mine, Utah, USA.
- Best Field Indicators are color, habit, associations, density and luster.