Ferroactinolita
Ferroactinolita is a mineral with formula Ca₂Fe²⁺₅Si₈O₂₂(OH)₂, in the Silicatos (Inosilicatos) group. This specimen comes from Cantera Juanona, Antequera, Málaga, Andalucía, España and joined the Terrium collection in 2024.
Description
Cluster of intense black prismatic crystals in a cavity on a greenish matrix. The crystals exhibit a metallic luster and good definition. Despite their fragility, they are well preserved within the natural cavity.
About Ferroactinolita
Ferro-actinolite, Ca₂Fe²⁺₅Si₈O₂₂(OH)₂, represents the iron-rich end member of the tremolite–actinolite series. It is the ferriferous counterpart of actinolite: the dominance of iron accounts for its higher density and its very dark green, greenish-brown or black tones. It usually occurs as prismatic or acicular crystals, or as fibrous aggregates, with a heavier and darker appearance than common actinolite.
About the locality
La Juanona Quarry (Antequera): A former 1990s ophite quarry and a classic Spanish collecting locality. It is famous for cavities featuring blue quartz and dark amphiboles (such as ferroactinolite and riebeckite) that contrast aesthetically against the greenish matrix.
Technical data
- Catalogue No.
- 0442
- Internal reference
- T0049
- Composition
- Ca₂Fe²⁺₅Si₈O₂₂(OH)₂
- Name
- Ferroactinolita
- Group
- Silicatos (Inosilicatos)
- Category
- Cavella
- Mine
- Cantera Juanona
- District / Municipality
- Antequera
- Province
- Málaga
- Region
- Andalucía
- Country
- España
- Size (cm)
- 6 x 4 x 4
- Weight
- 78.4 g
- Acquired
- 2024
- Ex-collection
- Amelia Molina
- Etymology
- From the latin ferrum and actinolite; iron rich on the series
- Quality
- Buena
- Value trend
- Estable
Related specimens
- Abellaíta — España
- Abernathyita — España
- Abernathyita — España
- Abernathyita — España
- Aerenita — España
- Aerinita (fibrosa) — España
- Analcima — España
- Analcima — España