Onyx
is a variety of microcrystalline silicon dioxide or chalcedony.
It is often banded with white and used for cameo carvings.
Most varieties of onyx, including black, are the result
of dying. These dyes have been
used for hundreds of years. Onyx is often used for rosary
beads, as the Christians held on to the pagan beliefs that
onyx had great medicinal benefits. Onyx was thought to make
wounds heal faster and childbirth go smoothly.
