Smithsonite

A soft stone which may be found occasionally cut en cabochon.

Named after James Smithson, who founded the Smithsonian Institution; it forms when zinc minerals are altered by weathering, particularly on limestone.

It is found in blue and green if containing copper; the presence of cobalt turns it pink to purple; cadmium makes it yellow and iron turns it reddish to brown; it is most often found in apple green - blue, but most sought after in lavender.