Baumite

Baumite is a medium brown to nearly black manganoan lizardite which, as with many serpentines. may be intergrown with minor amounts of chlorite. Clark [1993, "Hey's Mineral Index"] reports this as a species, but Nickel and Nichols [1991, "Mineral Reference Manual"] regarded it as 'a mixture of several serpentines and chlorites', quoting Frondel and Ito, (American Mineralogist, 1975) For accuracy, "baumite" is not a variety of lizardite, but rather a mixture of lizardite, zincian caryopilite/zincian greenalite, and chlorite group phases. See added references for greater detail.