#pyorxene

The blue color in this case reportedly comes from a small amount of the element manganese in the mineral structure. Elements like manganese – transition metals, found in the middle of the periodic table, often contribute strong colors when they’re present because the electrons interact strongly with visible light. That’s why iron gives a strong red color to rust and why manganese gives this pyroxene, called violane, such a lovely blue color. Blue pyroxenes can also be produced by chromium getting stuck in the mineral, similar to how the manganese behaves in this case.

This sample is 32 millimeters across at its widest point.

-JBB

Image credit: https://flic.kr/p/p1yDnx