From The Collaborative International Dictionary of English v.0.48 [gcide]:
Lazulite \Laz"u*lite\, n. [From lazuli : cf. F. lazulite, G.
lazulith.] (Min.)
A mineral of a light indigo-blue color, occurring in small
masses, or in monoclinic crystals; blue spar. It is a hydrous
phosphate of alumina and magnesia.
[1913 Webster]