| Wavellite | |
| Category: | Phosphate minerals |
| Formula: | Al3(PO4)2(OH,F)3·5H2O |
| Imasymbol: | Wav[1] |
| Strunz: | 8.DC.50 |
| System: | Orthorhombic |
| Class: | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
| Symmetry: | Pcmn |
| Unit Cell: | a = 9.621 Å b = 17.363 Å, c = 6.994 Å; Z = 4 |
| Color: | Green to yellowish-green and greenish blue and blue. and yellow, brown, white and colorless |
| Habit: | Spherical, radial aggregates; striated prisms; crusty to stalactitic |
| Cleavage: | [110] perfect, [101] good, [010] distinct |
| Fracture: | Uneven to subconchoidal |
| Mohs: | 3.5 - 4 |
| Luster: | Vitreous to resinous, pearly |
| Refractive: | nα = 1.518 - 1.535 nβ = 1.524 - 1.543 nγ = 1.544 - 1.561 |
| Opticalprop: | Biaxial (+) |
| Birefringence: | δ = 0.026 |
| Pleochroism: | Weak; X = greenish; Z = yellowish |
| 2V: | Measured: 60° to 72° |
| Streak: | White |
| Gravity: | 2.36 |
| Fusibility: | Infusable, swells and splits on heating |
| Solubility: | Insoluble |
| Diaphaneity: | Translucent |
| References: | [2] [3] [4] [5] |
Wavellite is an aluminium basic phosphate mineral with formula Al3(PO4)2(OH, F)3·5H2O. Distinct crystals are rare, and it normally occurs as translucent green radial or spherical clusters.[6]
Wavellite was first described in 1805 for an occurrence at High Down, Filleigh, Devon, England and named by William Babington in 1805 in honor of Dr. William Wavell (1750–1829),[4] a Devon-based physician, botanist, historian, and naturalist, who brought the mineral to the attention of fellow mineralogists.[7] [4] [6] [8]
It occurs in association with crandallite and variscite in fractures in aluminous metamorphic rock, in hydrothermal regions and in phosphate rock deposits.[2] It is found in a wide variety of locations notably in the Mount Ida, Arkansas area in the Ouachita Mountains.
It is sometimes used as a gemstone.[9]