Vivianite
A variety of Vivianite Group
What is Vivianite?
Vivianite is a soft, fragile mineral that grows in a wide variety of forms, occasionally creating very impressive crystals. Though it is colorless in its pure form, the mineral oxidizes quickly, often changing into a striking green or blue hue. Vivianite has no commercial or industrial uses, although attractive specimens are sought after by collectors.
Etymology & Origins
It was named by Abraham Gottlob Werner in 1817, the year of his death, after either John Henry Vivian (1785–1855), a Welsh-Cornish politician, mine owner and mineralogist living in Truro, Cornwall, England, or after Jeffrey G. Vivian, an English mineralogist. Vivianite was discovered at Wheal Kind, in St Agnes, Cornwall.
Uses & Applications
Vivianite is very popular among collectors as raw specimens and as gemstones. However, there are no known industrial or household uses for this mineral. Vivianite was historically once used as a pigment in oil paints, though it is rarely used in that context in modern times.
Healing Properties
Vivianite is believed to be a restorative stone that will help to remove negative energy from your emotional, physical and spiritual body and replace it with positive healing energy. It is said that just holding the crystal in the hand can revitalize the individual. It is often used to alleviate stress and help boost a more positive outlook, allowing an individual to move forward in life.
Optical Properties
- Refractive Index
- 1.560-1.640
- Birefringence
- 0.054-0.075
- Pleochroism
- Strong: deep blue, pale yellowish green, yellowish green
- Optical Character
- Biaxial positive
Vivianite Market Value Calculator
Estimate the market value of Vivianite using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.
Vivianite Localities Map
See where Vivianite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
Associated Chakras
Key Characteristics
Characteristics of Vivianite
Vivianite is a soft mineral, with Mohs hardness only 1 ⁄2 to 2, and specific gravity 2.7. It splits easily, with perfect cleavage perpendicular to the b crystal axis, due to the sheet-like structure of the mineral. It is sectile, with a fibrous fracture, and thin laminae parallel to the cleavage plane are flexible. It is easily soluble in acids. It has a melting point of 1,114 °C (2,037 °F), it darkens in color in H2O2 and is not radioactive.
Appearance of Vivianite
The mineral may occur as crystals, or as masses or concretions. The crystals are usually prismatic parallel to the c crystal axis, and flattened perpendicular to the b axis. Equant crystals are rarer. They may also occur as stellate (star-shaped) groups, or encrustations with a bladed or fibrous structure. Unaltered specimens are colorless to very pale green, but they oxidize on exposure to light (and possibly also in situ) to blue, then darker green, brown, purple and purplish black. The streak is white, altering to dark blue or brown. Crystals are transparent to translucent with a vitreous luster, pearly on the cleavage surface, or dull and earthy.
Composition of Vivianite
In pure end member vivianite all the iron is divalent, Fe, but there are two distinct sites in the structure that these ions can occupy. In the first site the Fe is surrounded by four water molecules and two oxygens, making an octahedral group. In the second site the Fe is surrounded by two water molecules and four oxygens, again making an octahedral group. The oxygens are part of the phosphate groups (PO4), that are tetrahedral. The vivianite structure has chains of these octahedra and tetrahedra that form sheets perpendicular to the a crystal axis. The sheets are held together by weak bonds, and that accounts for the perfect cleavage between them. The crystals are monoclinic, class 2/m, space group C 2/m, with two formula units per unit cell (Z = 2). The approximate values of the unit cell parameters are a = 10.1 Å, b = 13.4 Å, c = 4.7 Å and β = 104.3°, with slightly different values given by different sources: a = 10.086 Å, b = 13.441 Å, c = 4.703 Å, β = 104.27° a = 10.06 Å, b = 13.41 Å, c = 4.696 Å, β = 104.3° a = 10.034–10.086 Å, b= 13.434–13.441 Å, c= 4.687–4.714 Å, β = 102.65–104.27° a = 10.024(6) Å, b = 13.436(3) Å, c = 4.693(4) Å, β = 102.30(5)°
More Images
Quick Facts
Physical Properties
- Color
- Colourless and transparent when fresh, quickly turning pale to deep blue, greenish-blue or bluish-green
- Hardness (Mohs)
- 1.5 - 2
- Density
- 2.696 g/cm³
- Streak
- Colourless to bluish white, quickly changing to dark blue or brown
- Luster
- Pearly, Vitreous, Dull
- Crystal System
- Monoclinic
Chemical Properties
- Chemical Formula
- Fe2+3(PO4)2 · 8H2O
- Elements
- Fe, H, O, P
Also Known As
Identify Vivianite Instantly
- Snap a photo, get instant results
- 6,700+ rocks, minerals & crystals
- Discover collecting spots near you
