vivianite

[ viv-ee-uh-nahyt ]
/ ˈvɪv i əˌnaɪt /

noun

a secondary mineral, hydrous ferrous phosphate, Fe3(PO4)2⋅8H2O, occurring in the form of pale blue crystals or powder.

Origin of vivianite

1815–25; named after J. G. Vivian, 19th-century English mineralogist, who found it; see -ite1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019