Feldspath ::
Feldspath (n.) A name given to a group of
minerals, closely related in
crystalline form, and all
silicates of
alumina with
either potash, soda, lime, or, in one case,
baryta. They occur in
crystals and
crystalline masses, vitreous in
luster, and
breaking rather easily in two
directions at right
angles to each
other, or
nearly so. The
colors are
usually white or
nearly white, flesh-red, bluish, or
greenish..