SCHILLER n.
certain minerals, as hypersthene, schiller spar, etc. It is due to the presence of minute inclusions in parallel position, and in sometimes of secondary origin. Schiller spar (Min.), an altered variety of enstatite, exhibiting, in certain positions, a bronzelike luster.
ZONAL a.
-- Zonal structure (Crystallog.), a structure characterized by the arrangements of color, inclusions, etc., of a crystal in parallel or concentric layers, which usually follow the outline of the crystal, and mark the changes that have taken place during its growth. -- Zonal symmetry. (Biol.) See the Note under Symmetr…