Mereheadite

Mereheadite
General
Category Halide
Formula
(repeating unit)
Pb47Cl25(OH)13O24(CO3)(BO3)2
Strunz classification 03.DC.45
Crystal system Monoclinic
Space group Monoclinic, Domatic H–M Symbol m
Unit cell

a = 17.372(1) Å, b = 27.9419(19) Å, c = 10.6661(6) Å

β = 93.152(5)°
Identification
Color Pale yellow
Mohs scale hardness
Luster Vitreous, resinous
Streak White
Optical properties Biaxial
Refractive index nα = 2.190 nγ = 2.280
Birefringence δ = 0.090
References [1][2][3]

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


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