And besides, it presents traces of potassium.
The
cyanite is found in granite, and in the micaceous schist of primitive
mountains, either in masses or disseminated. The primitive form seems
to be a quadrangular oblique prism, having watered, brilliant iridized
facets. Easily broken, it has a double cleavage, and is translucent
and sometimes transparent.
It is found in Asia, Europe, and America, and is also procured from St. Gothard and England.
It
is easily distinguished from the blue corundum or Oriental sapphire,
although in India it is cut so as to imitate the latter gem, with the
view of selling it deceptively at a high price.
