Iolite \I"o*lite\ ([imac]"[-o]*l[imac]t), n. [Gr. 'i`on a violet
+ -lite.] (Min.)
A silicate of alumina, iron, and magnesia, having a bright
blue color and vitreous luster; cordierite. It is remarkable
for its dichroism, and is also called {dichroite}. A variety
called {Caribbean iolite} has a lighter blue color.
[1913 Webster +PJC]