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Granate Melanita (Andradita)

Granate is a mineral with formula Ca₃(Fe³⁺,Ti)₂(SiO₄)₃, in the Silicato [Granate (tectosilicato especial) + Epidota (Sorosilicato) + Cuarzo (Tectosilicato)] group. This specimen comes from Cantera Los Serranos, Hondón de los Frailes, Alicante, Comunidad Valenciana, España and joined the Terrium collection in 1983.

Granate Melanita (Andradita) from Cantera Los Serranos, Hondón de los Frailes, Alicante, Comunidad Valenciana, España — Terrium

Description

Lustrous, well-defined black cubes of andradite (var. melanite) on fan-shaped aggregates of green crystallised epidote. Small colourless quartz crystals are interspersed among them.

History of this specimen

It belonged to the collection of Antonio Barahona, one of the most influential collectors in the Spanish mineralogical scene, with species even bearing his name. The piece dates to 1983 and I acquired it directly from his son after a long conversation in which Tábata, Barahona’s granddaughter, also took part, likewise keen on minerals—a notable fact, as this passion rarely survives the generational handover. It came in a hand-made case they had built themselves, with a carved wooden base and red velvet. The original label identified the specimen as "garnet" and "pistacite", terms common at the time but now obsolete. "Pistacite" designated iron-rich epidote, consistent with the age of the piece.

About Granate

Andradite is a calcium garnet in the nesosilicate group; its melanite variety is notable for its black colour due to high titanium content. Epidote is a calcium–iron sorosilicate, traditionally called "pistacite". In this piece andradite (garnet group), epidote (sorosilicate), and quartz (tectosilicate) occur together. Three distinct silicate architectures in a single matrix.

About the locality

The deposit lies on Carmelo’s estate, a unique figure as the last jet carver in Spain; he safeguards the site and extracts these pieces (the so-called "clinos", which are in fact epidotes). Los Serranos Quarry (Albatera, Alicante) works a dolerite outcrop in Triassic Keuper facies. Operations began in the 20th century and continue today. The locality is noted for plates coated with epidote, andradite and quartz formed in hydrothermal cavities. Taxonomic confusions were frequent in the past, but it is now known that epidote is the predominant mineral. Well-crystallised specimens like this are increasingly scarce.

Technical data

Catalogue No.
0190
Composition
Ca₃(Fe³⁺,Ti)₂(SiO₄)₃
Name
Granate
Variety
Melanita (Andradita)
Group
Silicato [Granate (tectosilicato especial) + Epidota (Sorosilicato) + Cuarzo (Tectosilicato)]
Category
Cresta Montis
Matrix
cuarzo
Associations
epidota cuarzo
Mine
Cantera Los Serranos
District / Municipality
Hondón de los Frailes
Province
Alicante
Region
Comunidad Valenciana
Country
España
Size (cm)
10 x 8 x 4
Acquired
1983
Ex-collection
Antonio Barahona
Etymology
From the Greek "epidosis" ("addition"), in reference to the parallel growth of the crystals.
Quality
Notable
Value trend
Al alza

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