Identification guide · Phosphate Minerals
How to Identify Vivianite
Vivianite is usually blue, green, and colorless with a vitreous luster and is translucent. It has a Mohs hardness of 1.75. A fingernail (Mohs 2.5) scratches it easily. Its streak is bluish white. It is most often confused with Calcite, Celestine, and Cerussite; the tests below separate them.
Vivianite identification checklist
| Color | Blue, Green, Colorless | Look at a clean, dry surface in daylight. Color zoning, banding or spots are as diagnostic as the hue. |
|---|---|---|
| Luster | Vitreous | Fresh surfaces shine like glass; a dull surface usually means weathering, so chip or wet a corner. |
| Transparency | Translucent | Hold a thin edge up to a bright light and note whether light passes through. |
| Mohs hardness | 1.75 | A fingernail (Mohs 2.5) scratches it easily. |
| Streak | Bluish white | Drag a corner across unglazed porcelain (the back of a bathroom tile) and check the powder color. |
| Cleavage | Perfect | |
| Fracture | Fibrous | |
| Specific gravity | 2.68 | Ordinary rock-like heft (specific gravity about 2.68), similar to quartz. |
| Crystal system | Monoclinic |
Vivianite look-alikes and how to tell them apart
Calcite is harder (Mohs 3) than Vivianite (Mohs 1.75), so Calcite will scratch Vivianite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Vivianite vs Calcite →
Celestine is harder (Mohs 3–3.5) than Vivianite (Mohs 1.75), so Celestine will scratch Vivianite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Vivianite vs Celestine →
Cerussite is harder (Mohs 3–3.5) than Vivianite (Mohs 1.75), so Cerussite will scratch Vivianite and not the other way round. A fingernail (Mohs 2.5) scratches it easily. Vivianite vs Cerussite →
Both sit near Mohs 1.75, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
Field tips
- Look for deep blue to green bladed or prismatic crystals with a perfect cleavage.
- Extreme softness, easily scratched by a fingernail, helps distinguish vivianite.
- Darkening of color on exposure to light supports identification.
Vivianite identification FAQ
How can you tell if a rock is Vivianite?
Check the color (blue, green, and colorless), the vitreous luster, a Mohs hardness of 1.75 and a bluish white streak. Photographing it with the StoneSnap app gives a match in seconds.
What is the hardness of Vivianite?
Vivianite has a Mohs hardness of 1.75. A fingernail (Mohs 2.5) scratches it easily.
What is the difference between Vivianite and Calcite?
Vivianite (Mohs 1.75, vitreous luster) and Calcite (Mohs 3, vitreous luster) look alike, but hardness, streak and heft usually separate them. See the full Vivianite vs Calcite comparison for a side-by-side table.
Is Vivianite worth anything?
Entry-level Vivianite specimens sell for around $10, typical collector pieces about $60, and premium examples $400 or more depending on size, quality and locality.
What color is Vivianite?
Vivianite is most often blue, green, and colorless. Color varies with impurities and locality, so confirm with hardness and luster rather than color alone.
