Source : Webster's Revised Unabridged Dictionary (1913)

Kieserite \Kie"ser*ite\ n. [Named after Prof. Kieser, of Jena.]
   (Min.)
   Hydrous sulphate of magnesia found at the salt mines of
   Stassfurt, Prussian Saxony.

Source : WordNet®

kieserite
     n : a white mineral consisting of hydrous magnesium sulfate
         often found in salt mines