The Collaborative International Dictionary of English v.0.48:

Ligure \Lig"ure\ (l[i^]g"[-u]r; 277), n. [L. ligurius, Gr.
   ligy`rion, liggoy`rion, ligkoy`rion, lygkoy`rion, equiv. to
   Heb. leshem.]
   A kind of precious stone.
   [1913 Webster]

         The third row a ligure, an agate, and an amethyst.
                                                  --Ex. xxviii.
                                                  19.
   [1913 Webster]

Easton's 1897 Bible Dictionary:

Ligure
   (Heb. leshem) occurs only in Ex. 28:19 and 39:12, as the name of
   a stone in the third row on the high priest's breastplate. Some
   have supposed that this stone was the same as the jacinth
   (q.v.), others that it was the opal. There is now no mineral
   bearing this name. The "ligurite" is so named from Liguria in
   Italy, where it was found.