Brazilian Black Sardonyx earrings, where to start to describe Sardonyx. Well it is a highly polished semi precious stone. The name Sardonyx derives from the word “Sard & Onyx relating to the stripes, that’s if there is any. which is a contradiction in its own description. Leaving out the technical description, these earrings are made up using Black Sardonyx Semi-Precious Beads, 3 Swarovski Xillion cut bicones mounted on gold plated ear-wires.
Onyx is formed with bands of chalcedony in alternating colours. It is cryptocrystalline, consisting of fine inter-growths of the silica minerals quartz and morganite. Its bands are parallel to one another, as opposed to the more chaotic banding that often occurs in agates.
Sardonyx is a variant in which the coloured bands are sard (shades of red) rather than black. Black onyx is perhaps the most famous variety, but is not as common as onyx with coloured bands.