/trid"euh muyt'/ , n. Mineral.
a polymorph of quartz occurring in the form of small crystals, commonly twinned, in siliceous volcanic rocks.
[ 1865-70; Tridymit, equiv. to tridym- (Gk trídym ( os ) triple, equiv. to tri- TRI- + ( dí ) dymos DIDYMOUS) + -it -ITE 1 ]