Vivianite is a hydrated iron phosphate mineral prized for its stunning, deep blue to green prismatic crystals. It is famously light-sensitive; freshly mined crystals may appear colorless or pale, but they darken rapidly when exposed to light, so specimens should be stored in the dark.
Is this vivianite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch vivianite with a known reference. Vivianite sits at Mohs 1.5-2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white, altering to dark blue, brown.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous, pearly on the cleavage, dull when earthy.
- 4Match the color rangeCompare against the expected color range: colorless, white, pale green, dark blue, deep blue-green, indigo, green, blue, dark green, dark bluish green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: concretionary, divergent, earthy.
Often confused with
Vivianite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside vivianite
Minerals reported to co-occur with vivianite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Fe₃(PO₄)₂·8H₂O
- Mohs hardness
- 1.5-2
- Density
- 2.68 g/cm³
- Colors
- Streak
- White, altering to dark blue, brown
- Luster
- Vitreous, pearly on the cleavage, dull when earthy
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Concretionary, divergent, earthy
- Cleavage
- Perfect on {010}
- Rarity
- Common
- Uses
- Collector, Mineral specimen
- Host rock
- A secondary mineral in the oxidized zone of metallic ore deposits and complex granite pegmatites; replacing organic material in fossil bones, lake sediments, and in bog-iron ores and peat bogs; rarely in caves
Where rockhounds find vivianite
5 mapped spotsClassic worldwide localities
- Blackbird Mine, Lemhi Co., Idaho, USA
- Treece and Ibex mines, Leadville, Lake Co., Colorado, USA
- Bingham Canyon mine, Salt Lake Co., Utah, USA
- Richmond, Henrico Co., Virginia, USA
- Hagendorf, Bavaria, Germany
- Stari Trg mine, Trepča, Serbia
Field-hunting tip
Where it forms: A secondary mineral in the oxidized zone of metallic ore deposits and complex granite pegmatites; replacing organic material in fossil bones, lake sediments, and in bog-iron ores and peat bogs; rarely in caves. If you start seeing metavivianite, ludlamite, pyrite in float, you are in the right ground. Typical habit: concretionary, divergent, earthy. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Alabama, Florida, Missouri. Start trip planning there.
Common questions
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Find vivianite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
