The Collaborative International Dictionary of English v.0.48:

Cipolin \Cip"o*lin\, n. [It. cippollino, prop., a little onion,
   fr. cipolla onion (cf. E. cibol). So called because its veins
   consist, like onions, of different strata, one lying upon
   another.] (Min.)
   A whitish marble, from Rome, containiing pale greenish zones.
   It consists of calcium carbonate, with zones and cloudings of
   talc.
   [1913 Webster]