Ludlamite

(Fe,Mn,Mg)3(PO4)2·4H2OIMA symbolLud[1]Strunz classification8.CD.20Crystal systemMonoclinicCrystal classPrismatic (2/m)
(same H-M symbol)Space groupP21/aUnit cella = 10.541(5), b = 4.646(4)
c = 9.324(5) [Å]; β = 100.52°; Z = 2IdentificationColorApple-green to bright greenCrystal habitTabular crystals; massive, granularCleavageCleavage: perfect on {001}, indistinct on {100}Mohs scale hardness3.5LusterVitreous, pearly on cleavageStreakPale greenish whiteDiaphaneityTranslucentSpecific gravity3.12–3.19Optical propertiesBiaxial (+)Refractive indexnα = 1.650 - 1.653 nβ = 1.669 - 1.675 nγ = 1.688 - 1.697Birefringenceδ = 0.038 - 0.0442V angleMeasured: 82°References[2][3][4]

Ludlamite is a rare phosphate mineral with chemical formula (Fe,Mn,Mg)3(PO4)2·4H2O. It was first described in 1877 for an occurrence in Wheal Jane mine in Cornwall, England and named for English mineralogist Henry Ludlam (1824–1880).

Occurrence

It occurs in granite pegmatites and as a hydrothermal alteration product of earlier phosphate bearing minerals in a reducing environment.[4] It occurs associated with whitlockite, vivianite, triploidite, triplite, triphylite, siderite, phosphoferrite, fairfieldite and apatite.[2]

References

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b Mindat.org
  3. ^ Webmineral.com
  4. ^ a b Handbook of Mineralogy

Media related to ludlamite at Wikimedia Commons


  • v
  • t
  • e