-rəˌtȯid noun
( -s )
Etymology: German, from chlorit chlorite (mineral) + -oid
: a mineral (Mg 1 Fe)AlSiAlO 5 (OH) 2 consisting of a silicate of aluminum and ferrous iron with magnesium occurring usually in dull green to gray or grayish black masses of brittle folia and related to the brittle micas (as clintonite)