A freeform style pendant set with psilomelane, a mixture of black manganese oxide minerals. Psilomelane is often found naturally banded with a gray material called pyrolusite, giving it alternating stripes of metallic gray and submetallic black.
In the case of this particular stone, in addition to the banding there is also a material in the layers that gives it a bluish glow when viewed at the correct angle under natural light. So far, no one has been able to explain why this particular material, which came from the Yucatan, exhibits this unusual "glowing" phenomenon.
Fabricated 14k yellow gold and psilomelane.
Alberto Kerbow, 2002.