LIZARDITE

Lizardite is a mineral belonging to the serpentine subgroup, characterized by the chemical formula Mg3(Si2O5)(OH)4, and is recognized as the most prevalent mineral within this subgroup. Additionally, it is classified under the kaolinite-serpentine group. Lizardite can form a solid-solution series with the nickel-rich mineral népouite, which has the formula Ni3(Si2O5)(OH)4. Intermediate compositions, represented as (Mg,Ni)3(Si2O5)(OH)4, can occur with varying amounts of magnesium and nickel; however, lizardite is significantly more abundant than the rarer népouite, which typically arises from the alteration of ultramafic rocks. The mineral is often found in extremely fine-grained, scaly forms known as orthoantigorite, which constitute a large portion of the serpentine found in "serpentine marbles." Lizardite exhibits a triclinic crystal system, possesses perfect cleavage in one direction, and can appear in colors such as white, yellow, or green. Its texture may range from translucent to opaque, often with a soapy feel. In some cases, lizardite can take on a pseudomorphous form after minerals like enstatite, olivine, or pyroxene, leading to the designation of bastite, which may exhibit a silky luster. The mineral was named in 1955 by Eric James William Whittaker and Jack Zussman, after the Lizard Peninsula in southern Cornwall, England, where it was first identified. Scyelite is recognized as a synonym for lizardite.