lanarkite

from The Century Dictionary.

• noun A basic sulphate of lead occurring in greenish-white or pale-yellow monoclinic crystals at Leadhills in Lanarkshire, Scotland.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Min.) A mineral consisting of sulphate of lead, occurring either massive or in long slender prisms, of a greenish white or gray color.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mineralogy A mineral form of lead sulfate with the chemical formula Pb2(SO4)O, an oxidation product of galena, whose acicular monoclinic prismatic crystals are white or light green.