Vivianita
Vivianita is a mineral with formula Fe²⁺₃(PO₄)₂·8H₂O, in the Fosfatos group. This specimen comes from Mina Siglo Veinte, Llallagua, Rafael Bustillo, Potosí, Bolivia and joined the Terrium collection in 2025.
Description
Single, elongated square prism, gem quality, very dark green with several bluish reflections on one face; transparent in transmitted light, with inclusions producing phantoms and longitudinal parallel growth.
About Vivianita
Hydrated iron phosphate considered a "necromineral" due to its origin in the interaction between organic phosphates and iron, that is, between post-mortem organic remains. Photosensitive: it darkens over time as it oxidises, changing from blue to green.
About the locality
Historic tin district that in 1967 was the scene of the country's largest workers' massacre, and twenty years later would close by IMF imposition, ending state-run mining. Today it is worked by self-managed cooperatives and these vivianite specimens are increasingly difficult to find.
Technical data
- Catalogue No.
- 0484
- Internal reference
- T0093
- Composition
- Fe²⁺₃(PO₄)₂·8H₂O
- Name
- Vivianita
- Group
- Fosfatos
- Category
- Estélites
- Mine
- Mina Siglo Veinte
- District / Municipality
- Llallagua
- Province
- Rafael Bustillo
- Region
- Potosí
- Country
- Bolivia
- Size (cm)
- 6.5 x 0.7 x 0.7
- Acquired
- 2025
- Etymology
- Named in honour of John Henry Vivian (1785–1855), British mineralogist and politician, who discovered it in 1817.
- Quality
- Buena
- Value trend
- Estable