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Webster 1913 Edition
Epistilbite
Epˊi-stil′bite
,Noun.
 [Pref. 
epi- 
+ stilbite
.] (Min.) 
A crystallized, transparent mineral of the Zeolite family. It is a hydrous silicate of alumina and lime. 
Webster 1828 Edition
Epistilbite
EPISTIL'BITE
,Noun.