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 vug lined with highly lustrous, dark sea-green vivianite needles up to 2.8 cm long, aesthetically set within the matrix.
Vivianite Physical Properties
Mohs Hardness
1.5Crystal System
monoclinicLuster
vitreousStreak Color
bluish whiteCleavage
perfect on {010}Fracture
fibrousSpecific Gravity
2.65Colors
colorless, pale green, blue, dark blue, blackTransparency
transparentType Locality
Kerch peninsula, Crimea peninsula, Crimea Oblast', UkraineMineral Group
PhosphatesUses
collector, pigmentAssociated Minerals
pyrite, siderite, sphalerite, apatiteRarity
uncommonGeological Context
Vivianite typically forms in low-temperature hydrothermal veins, pegmatites, and as a secondary mineral in altered igneous and metamorphic rocks. It is also found in sedimentary environments, particularly in peat bogs, clay deposits, and fossil-rich sediments, often associated with iron ore deposits and fossil shells.
