Also They sold in market with the name „Black Jasper „ Description The term onyx originally comes from the Greek word ónychos, which can be translated as fingernail. Over a longer period of time, onyx was used as a term for all agates, as they resemble fingernails due to their colored bands. Another explanation for the name is that the top, white layer of the onyx laystone is slightly transparent - like fingernails. Since the 18th century, the monochrome black chalcedony has also been referred to as onyx. This onyx is the black variety of chalcedony, a microcrystalline gemstone from the quartz group. Onyx is both a chalcedony in a velvety matt black and an agate, which is composed of two or more layers of different colors Mining area Localities for onyx and sardonyx include Yemen, Brazil, Madagascar, Mexico, Pakistan , Crete, Greece, Uruguay and the USA.