TERRIUM — A mineralogy cabinet


Adamita

Adamita is a mineral with formula Zn₂AsO₄(OH), in the Arseniatos group. This specimen comes from Mina Ojuela, Mapimí, Durango, México and joined the Terrium collection in 2026.

Adamita from Mina Ojuela, Mapimí, Durango, México — Terrium

Description

A dominant lemon-yellow main crystal with exceptional crystallisation, set in a limonite cavity with a microbotryoidal lining speckled with blue-metallic iridescent goethite. Under magnification, no contacts or detachment are observed. On the reverse, a small additional crystal is present.

About Adamita

A secondary mineral formed by oxidation, this zinc hydroxyarsenate from Mina Ojuela typically shows two distinguishing features: lemon-yellow colour (adamite is usually colourless) and strong fluorescence due to uranyl traces. Adamite is relatively common and inexpensive when lacking well-developed crystals. Pieces of this calibre are very difficult to find. Still finer ones are few and often priced for other markets.

About the locality

Mina Ojuela, at Mapimí, is one of the world's best-known localities for secondary zinc and arsenic minerals. It has produced some of the most famous adamite and cuprian adamite ever found, along with mimetite and hemimorphite also highly regarded in the mineral-collecting world. At its mining peak, the complex was linked to the town by a spectacular, if spartan, suspension bridge built in 1898 by the same company as the Brooklyn Bridge. A few kilometres away lies the legendary "Zone of Silence", a place wrapped in legends about radio anomalies and various meteorites; this layer of mystical-esoteric folklore, together with the mine's exceptional crystals, has made Mina Ojuela a site where major mineralogy meets the desert imaginary.

Technical data

Catalogue No.
0406
Composition
Zn₂AsO₄(OH)
Name
Adamita
Group
Arseniatos
Category
Lucimera
Matrix
limonita
Associations
Goethita
Mine
Mina Ojuela
District / Municipality
Mapimí
Region
Durango
Country
México
Size (cm)
6 x 4.5 x 4.5
Weight
150 g
Acquired
2026
Ex-collection
Jesús Paterna
Etymology
Although it shares a lexical root with "diamond" via the Greek "adamas", this is mere coincidence. For a mineral of hardness 3.5 the name would be ironic; the reality is more functional. An eponym like many others, it honours Gilbert-Joseph Adam, who brought the specimens from Chañarcillo, Chile, its type locality.
Quality
Muy buena
Value trend
Al alza

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