Onyx
Like hematite, this stone if often but not always a glossy black. It may be white, orange, green, yellow or cream. Onyx is a banded chalcedony and thus often features attractive stripes, as seen in the picture on the left.
An interesting association I have with this stone is the onyx wall featured in the modernist house in Simon Mawer's novel, The Glass Room.
Onyx is ideal for making cameo jewellery. It is carved so that the white figures contrast with the black ground.
