Mereheadite
CategoryHalide
FormulaPb47Cl25(OH)13O24(CO3)(BO3)2
ImasymbolMrh[1]
Strunz3.DC.45
SystemMonoclinic
ClassPrismatic (2/m)
(same H-M symbol)
SymmetryC2/c
Unit cella = 17.372(1) Å,
b = 27.9419(19) Å,
c = 10.6661(6) Å;
β = 93.152(5)°; Z = 2
ColorPale yellow
Mohs3 1⁄2
LusterVitreous, resinous
StreakWhite
OpticalpropBiaxial
Refractivenα = 2.190 nγ = 2.280
Birefringenceδ = 0.090
References[2][3][4][5]

Mereheadite is a rare oxychloride that can be found with Mendipite at Merehead quarry, Cranmore, Somerset, in the United Kingdom. Most specimens are associated with calcite, mendipite or hydrous cerussite in the Manganese pods on vein two at torr works quarry (merehead quarry). This mineral is associated with symesite which is also light yellow to orange. Symesite is found in small blotches on the calcites or mendipites; Mereheadite does not, as it is most often found in veins.

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. ^ Mineralienatlas
  3. ^ Mindat.org
  4. ^ Webmineral.com
  5. ^ Handbook of Mineralogy