Cianita
Cianita is a mineral with formula Al₂SiO₅, in the Silicatos (Nesosilicatos) group. This specimen comes from Barra do Salinas, Coronel Murta, Minas Gerais, Brasil and joined the Terrium collection in 2025.
Description
Aggregates of intense blue kyanite crystals, with elongated, flattened prismatic habit, associated with white calcite and hyaline quartz. Under UV light the calcite shows orange fluorescence.
About Cianita
Kyanite is an aluminium nesosilicate characteristic of high-grade metamorphic environments, especially in aluminous schists and gneisses. It is recognised by its elongated prismatic habit and intense blue colour. A distinctive feature is that it does not have the same hardness in all directions: scratched along the length it is relatively soft, whereas scratched perpendicular to the length it is much harder.
About the locality
The Barra do Salinas area, in northeastern Minas Gerais, lies within a broad metamorphic context where kyanite occurs associated with quartz and carbonates. It is a source known in the Brazilian market for well-coloured aggregates, though without continuous historic production.
Technical data
- Catalogue No.
- 0066
- Composition
- Al₂SiO₅
- Name
- Cianita
- Group
- Silicatos (Nesosilicatos)
- Category
- Lucimera
- Associations
- cuarzo hialino, calcita
- Mine
- Barra do Salinas
- District / Municipality
- Coronel Murta
- Province
- Minas Gerais
- Country
- Brasil
- Size (cm)
- 15.6 x 2.6 x 2.2
- Weight
- 134 g
- Acquired
- 2025
- Etymology
- From the Greek "kyanos" (κύανος), meaning "blue", in direct reference to its characteristic colour.
- Quality
- Buena
- Value trend
- Estable
Related specimens
- Ágatha — Brasil
- Cianita (Negra) — Brasil
- Cianita (Negra (Taramita)) — Brasil
- Clinocloro — Italia
- Amatista — Brasil
- Cuarzo — Brasil
- Elbaíta (Verdelita) — Brasil
- Elbaíta (Verdelita) — Brasil