Barstowite, formula Pb₄ CO₃��H₂O, is a transparent to white mineral in the

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic s ...

system.Barstowite at Mindat.org mineralogical website
/ref> It has a

Mohs hardness The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by th ...

of 3, a white streak and an adamantine

lustre Lustre or Luster may refer to: Places * Luster, Norway, a municipality in Vestlandet, Norway ** Luster (village), a village in the municipality of Luster * Lustre, Montana, an unincorporated community in the United States Entertainment * '' ...

. The type locality for Barstowite is Bounds Cliff,

St Endellion St Endellion ( kw, Sen Endelyn) is a civil parish and hamlet in north Cornwall, England, United Kingdom. The hamlet and parish church are situated four miles (6.5 km) north of Wadebridge. The parish takes its name from Saint Endelienta, who ...

Cornwall Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...

in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

. It is named after Richard W. Barstow (1947–1982), a Cornish mineral collector.

References

Lead minerals Carbonate minerals Halide minerals Monoclinic minerals Minerals in space group 11 {{carbonate-mineral-stub