Coral

There are two main kinds of gem coral: percious coral which is typically red, pink orange or white, and black and golden coral.
The Romans believed coral would prevent childhood ailments, as well as using it as a charm against sterility. It is a soft material and is commonly fashioned as cabochons, beads, earring drops, cameos and carvings. It is easily attacked by acids and contact with cosmetics should be avoided. To clean use mild soapy water.
The pink coralsb> are characterized by a fine corrugation structure running along the lengths of the branches which is often visible in fashioned pieces. Black and golden coral displays concentric structures in the branches, similar to the growth rings of a tree, and have a distinctive subsurface pimply appearance.

Common treatments-

Precious coral may be stained, usually red or pink. Golden coral can be obtained by bleaching black coral.

Localities-

Today the majority of precious coral is from the seas to the south of Japan. Black coral is found in the West Indies, off the Hawaiian Islands, Australia and in southern waters towards Antarctica. There are strict controls on the fishing, export and import of coral in most countries.