Source : Webster's Revised Unabridged Dictionary (1913)

Sylvine \Syl"vine\, Sylvite \Syl"vite\, n. [So called from NL.
   sal digestivus sylvii potassium chloride.] (Min.)
   Native potassium chloride.

Source : WordNet®

sylvite
     n : a mineral consisting of native potassium chloride; an
         important ore of potassium that is found in sedimentary
         beds [syn: {sylvine}]