The Collaborative International Dictionary of English v.0.48:

Marmolite \Mar"mo*lite\ (m[aum]r"m[-o]*l[imac]t), n. [Gr.
   maramai`rein to sparkle + -lite.] (Min.)
   A thin, laminated variety of serpentine, usually of a pale
   green color.
   [1913 Webster]