4-1/2" Vivianite Crystal

Vivianite is a rare mineral known for changing from a colorless to a saturated blue-green. Light exposure causes internal oxidation, causing the permanent color change. It is a fragile mineral making it rare to find in jewelry or in faceted form. The natural crystals are prismatic, or tabular, growing in bladed groups of crystal clusters. It was discovered in the Wheal Kine mine in Cornwall, England, and named by the German geologist Abraham Gottlob Werner in 1817. It has been used as pigment in oil paintings since the Roman era (625 BC to 476 AD).