Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
monoclinicuncommonPhosphates
Vivianite
Fe3(PO4)2·8H2O
This specimen features a striking aggregate of dark blue to greenish-black, needle-like Vivianite crystals, forming a unique hedgehog-like shape.
Vivianite Physical Properties
Mohs Hardness
1.5Crystal System
monoclinicLuster
vitreousStreak Color
bluish whiteCleavage
perfect on {010}Fracture
unevenSpecific Gravity
2.68Colors
colorless, pale green, blue, dark blue, greenish-black, blackTransparency
transparentType Locality
Hesse, GermanyMineral Group
PhosphatesUses
collector, pigmentAssociated Minerals
pyrite, pyrrhotite, siderite, sphalerite, galena, quartz, apatite, limoniteRarity
uncommonGeological Context
Vivianite typically forms in low-temperature hydrothermal veins, pegmatites, and as an alteration product in fossil bones, shells, and peat bogs where iron and phosphate are present.
