A hand-knotted necklace and earring set made of Chalcedony and black fresh-water pearls. The necklace is 22 inches long.
Chalcedony, probably named after the city of Chalcedon in Asia Minor, is a member of the quartz family of minerals. It has been used as a semiprecious gem since at least the time of the Minoans and Egypt's First Dynasty (2000-3000 BC), and chalcedony flakes were used as tools in Australia circa 30,000 BC.
Chalcedony is silica (Silicon dioxide). The presence of Iron gives chalcedony a red color, the the result is Carnelian, used to make seals to stamp documents (on paper, papyrus, or clay-tablets). Add nickel to the mix and you have Chrysoprase. Other forms of chalcedony are Agate, Sardonyx, Heliotrope, Opal, and Jasper, depending on the additional elements present and the conditions at the time formation,
Silica is soluble, to a certain extent, and is the chief component in petrification of (once) living tissue; dinosaurs and tree trunks, for example.