Wavellite
Mineral Al3(PO4)2(OH,F)3·5H2O
About it
Radiating discs and green-yellow spheres that break open to show starbursts, often on joint faces in chert and shale. Superb from Mauldin Mountain and other sites in Arkansas; named for William Wavell of Devon.
- Type
- Mineral
- Group
- Phosphate
- Formula
- Al3(PO4)2(OH,F)3·5H2O
- Hardness (Mohs)
- 3.5–4
- Specific gravity
- 2.3–2.4
- Streak
- white
- Lustre
- vitreous (glassy), resinous, pearly
- Crystal system
- Orthorhombic
- Colours
- green, yellow-green, yellow, white, colourless, blue
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in two directions
Typical values: real specimens vary. For more, see mindat.org.