Mineral Database (Saesneg yn unig)

Mineral Database (Saesneg yn unig)

Hydroxylapatite

Crystal System: Hexagonal
Formula: Ca5(PO4)3(OH)
Status of Occurrence: Confirmed Occurrence
Distribution: Uncommon
Chemical Composition: Calcium phosphate hydroxide
Method(s) of Verification: Brynamman - XRD (Baqri & Hodson, 1979).
Chemical Group:
  • Phosphates
Geological Context:
  • Sedimentary : diagenetic
Introduction: hydroxylapatite belongs to the apatite group of minerals but is much less common than fluorapatite. It may form by the interaction of limestone with guano deposits.
Occurrence in Wales: only one occurrence of hydroxylapatite is known from Wales. Baqri & Hodson (1979) reported that coal partings or ‘dirt bands’ in the Lower Hornlo (Red Vein) seam in the neighbourhood of Brynamman, West Glamorgan contained up to 40% hydroxylapatite. This appears to be the first record of hydroxylapatite in the British Isles. The identification requires clarification.
Key Localities:
There are no key localities for this specimen.
References:
  • Baqri, R. & Hodson, F., 1979 Apatite in South Wales anthracite.  Geological Magazine, 30, 645-647.