cordierite


cordierite
cordierite [kôr′dē ər īt΄]
n.
[after P. L. A. Cordier (1777-1861), Fr geologist + -ITE1]
a bluish, very hard, pleochroic, crystalline mineral, magnesium aluminum silicate, (Mg,Fe) 2 Al4Si5O18, used sometimes as a gem

English World dictionary. . 2014.