Cordierite

Named after a French geologist Louis cordier cordierite is also called polite which means violet. It is famous for its trichroism having deep violet blue, blue grey and yellowish brown color.
Specifications
● Species: found in various regions such as Australia, Canada, Myanmar, Brazil, Madagascar, Namibia, Tanzania, Sri Lanka and the United States.
● Color: violet blue
● Clarity: translucent to transparent