Scapolite is a grayish white
mineral occurring in tetragonal crystals and in
cleavable masses. It is also called Wernerite.
It is basically a silicate of alumina and soda.
The structure of Scapolite is similar to some
feldspathoids in that it is composed of large
open spaces in the framework of silicate and aluminum
tetrahedrons. It forms in metamorphic rocks from
the alteration of plagioclase feldspars.
Scapolite derives from the Greek word for "shaft".
It is tetragonal with a square or octahedral cross-section.
It is difficult to identify Scapolite minerals
from each other as they differ slightly in density
and index of refraction. Due to this closeness
in properties and yet seemingly very different
chemistries, Scapolite has had its share of pseudonyms.
It is very popular owing to the bright colors
of its gemstones. The less transparent material
can be cut as cabochons. Rutilite is found in
the regions of New Jersey, New York in USA; Norway;
Mount Vesuvius, Italy and Mexico, Brazil, Madagascar,
Tremorgio, Switzerland and Burma.