TERRIUM — A mineralogy cabinet


Pachnolita

Pachnolita is a mineral with formula NaCaAlF₆·H₂O, in the Halogenuros group. This specimen comes from Ivigtut Mine, Arsuk Fjord, Sermeksoog, Groenlandia, Dinamarca and joined the Terrium collection in 1975.

Pachnolita from Ivigtut Mine, Arsuk Fjord, Sermeksoog, Groenlandia, Dinamarca — Terrium

Description

Halides.

History of this specimen

In Ivigtut, thomsenolite is more common and many historical pieces labelled as pachnolite have later been reviewed and corrected. For a definitive species confirmation I would need an XRD analysis. The piece originally came from a group of Danish collectors.

About Pachnolita

A rare hydrated sodium, calcium and aluminium fluoride, dimorph of thomsenolite, crystallising in cavities associated with cryolite (Na3AlF6) and forming acicular or fibrous aggregates. Pachnolite has its type locality at Ivigtut and is considered rare even within the already exceptional suite of hydrated halides from the deposit.

About the locality

A unique deposit on a global scale as the only exploitable natural source of cryolite. Active between 1865 and 1987, it had strategic importance during the Second World War due to its use in aluminium production. Famous for hosting more than 70 rare mineral species, many exclusive to the site. After closure, the mine flooded, preventing further extraction and consolidating the historical and collector value of recovered specimens, especially those from cavities with acicular growths.

Technical data

Catalogue No.
0147
Composition
NaCaAlF₆·H₂O
Name
Pachnolita
Group
Halogenuros
Category
Cavella
Associations
thomsenolita
Mine
Ivigtut Mine
District / Municipality
Arsuk Fjord
Province
Sermeksoog
Region
Groenlandia
Country
Dinamarca
Size (cm)
4.4 x 2.4 x 3.5
Weight
41 g
Acquired
1975
Ex-collection
SAF Denmark > Jakob Aandstad
Etymology
From the Greek "pachnós" (frost), referring to the white, crystalline appearance of its aggregates.
Quality
Muy buena
Value trend
Estable

Related specimens

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