Wavellite

Formula: Al3(PO4)2(OH,F)3 · 5H2O

Colour: Green to yellowish-green and yellow, greenish white, yellowish-brown, brown, brownish-black, blue, white and colourless; colourless in transmitted light.

Lustre: Vitreous, Greasy, Pearly

Hardness: 3½ – 4

Specific Gravity: 2.36

Crystal System: Orthorhombic

Member of: Wavellite Group

Name: Named by William Babington in 1805 in honor of Dr. William Wavell (1750–1829), a physician, botanist, historian, and naturalist who discovered the mineral. Non-contemporary accounts suggest that Dr. Wavell discovered phosphate in the mineral, a constituent that was previously missed in analyses of hydrargilite.

Type Locality: High Down Quarry (Heddon Quarry), West Buckland, North Devon, Devon – England, UK

A secondary mineral found most often in aluminous, low-grade metamorphic rocks. Usually found as radiating “starburst” clusters of green to yellow-green fibrous crystals on fracture surfaces in the matrix, these may grade into globular aggregates; more rarely in chalcedony-like or opaline masses, or stalactic; very rare as good distinct crystals. The OH analogue of fluorwavellite.