Ziose

Ziose was the name given by sages to a particular facet-grade variety of zoisite, a rare mineral that yielded cut stones that flashed three vivid hues depending on how the light caught them or in what direction they were viewed&mdash;purple, blue, and red, or purple, green, and red.

Description
Very large (fist- or foot-sized) specimens of these fancy stones were sometimes found and prized for use in pendants by humans, demihumans, and humanoids of large stature. A typical stone had a base value of 100 gp.

Also see

 * Rosaline