Bismuth

Bismuth, officially discovered in 1753 by French scientist Claude Geoffroy, is the chemical element Bi. It is naturally reddish-white to a creamy-white. It tarnishes beautifully into an iridescent bluish, pinkish, purplish and/or yellowish metallic color. It's soft, with a hardness of 2 - 2½.  All commonly seen in stair-step specimens are lab-grown.