Vivianite

 

Vivianite was named by Abraham Gottlob Werner in 1817 after John Henry Vivian, an English politician, mine owner, and mineralogist living in Truro, Cornwall, and discoverer of the mineral. When fresh, the mineral may be colorless, but once exposed, it will change to deep blue to deep bluish-green prismatic to flattened crystals.

Mineral Photos courtesy of R.Weller/Cochise College