Source : Webster's Revised Unabridged Dictionary (1913)

Lazuli \Laz"u*li\, n.[F. & NL. lapis lazuli, LL. lazulus,
   lazurius, lazur from the same Oriental source as E. azure.
   See {Azure}.] (Min.)
   A mineral of a fine azure-blue color, usually in small
   rounded masses. It is essentially a silicate of alumina,
   lime, and soda, with some sodium sulphide, is often marked by
   yellow spots or veins of sulphide of iron, and is much valued
   for ornamental work. Called also {lapis lazuli}, and
   {Armenian stone}.

Source : WordNet®

lazuli
     n : an azure blue semiprecious stone [syn: {lapis lazuli}]