Vivianite is a hydrated iron phosphate mineral prized for its intense, deep blue-green color. Collectors should note it is very soft and light-sensitive, often darkening to a deep blue or black upon exposure, so it should be stored in dark containers or light-protected displays.
Is this blue 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 blue vivianite with a known reference. Blue 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 to light blue.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: blue, green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals, radial aggregates, fibrous masses.
Often confused with
Blue Vivianite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Blue Vivianite leaves white to light blue, Annabergite leaves pale green to white; luster reads vitreous on Blue Vivianite and subadamantine, pearly on cleavages, may be dull, earthy on Annabergite.
How to tell apart: Streak differs, so Blue Vivianite leaves white to light blue, Erythrite leaves pale red to pink; luster reads vitreous on Blue Vivianite and subadamantine, pearly on cleavages on Erythrite.
Often found alongside blue vivianite
Minerals reported to co-occur with blue 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
- 2.64-2.68 g/cm³
- Streak
- White to light blue
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic crystals, radial aggregates, fibrous masses
- Cleavage
- Perfect {010}
- Rarity
- Uncommon
- Uses
- Collector, Display specimen
- Host rock
- sedimentary deposits, phosphate-rich zones, hydrothermal veins
Where rockhounds find blue vivianite
1 mapped spotsClassic worldwide localities
- Kertch Peninsula, Crimea
- Anloua, Cameroon
- Idaho, USA
- Cornwall, England
- Bolivia
Field-hunting tip
Where it forms: sedimentary deposits, phosphate-rich zones, hydrothermal veins. If you start seeing siderite, limonite, goethite in float, you are in the right ground. Typical habit: prismatic crystals, radial aggregates, fibrous masses. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Virginia. Start trip planning there.
More blue vivianite photos
Common questions
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Find blue vivianite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
