Tags: Chemical Substance, Mineral.
Madocite is a mineral with a general formula of Pb17(SbAs)16S41. Madocite was named for the locality of discovery Madoc Ontario Canada. It is found in the marbles of the Precambrian Grenville Limestone. It is orthorhombic (rectangular prism with a rectangular base) and in the point group mm2. Its crystals are elongated and striated along [001] to a size of 1.5 mm. Madocite is anisotropic and classified as having high relief.