TERRIUM — A mineralogy cabinet


Antigorita

Antigorita is a mineral with formula (Mg,Fe)3Si2O5(OH)4, in the Filosilicatos group. This specimen comes from Pedreira, Serra da Colada, A Coruña, Galicia, España and joined the Terrium collection in 2025.

Antigorita from Pedreira, Serra da Colada, A Coruña, Galicia, España — Terrium

Description

Fibrous, compact laminae of yellowish-green antigorite, with a silky lustre on fracture surfaces, typical of serpentinites formed by hydrothermal alteration of mantle peridotites and dunites.

History of this specimen

Collected by Óscar and me at an outcrop on the upper crest of the Serra da Colada on the road from Cariño to San Andrés de Teixido. We marked the spot to return, as there are more flakes or slabs of this type of serpentinite.

About Antigorita

Antigorite is a member of the serpentine group, with platy to columnar habit and a silky lustre. It is distinguished from chrysotile by its more stable structure and non-asbestiform habit. A typical mineral of hydrated ultramafic rocks.

About the locality

Cabo Ortegal is one of the most important ophiolitic complexes in Europe, where peridotites and serpentinites crop out, representing sections of the Earth's upper mantle. It is a reference locality for understanding the formation of the oceanic lithosphere and the associated metamorphic processes.

Technical data

Catalogue No.
0338
Internal reference
T0010
Composition
(Mg,Fe)3Si2O5(OH)4
Name
Antigorita
Group
Filosilicatos
Mine
Pedreira
District / Municipality
Serra da Colada
Province
A Coruña
Region
Galicia
Country
España
Size (cm)
4 x 3 x 1.5
Weight
25 g
Acquired
2025
Etymology
The name comes from the locality of Antigorio (Piedmont, Italy), where it was first described.
Quality
Buena
Value trend
Estable

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