Ericlaxmanite

Chemical formula: Cu<sup>2+</sup><sub>4</sub>O(As<sup>5+</sup>O<sub>4</sub>)<sub>2</sub>

Ericlaxmanite is a very rare copper arsenate, forming characteristic, blue-green, tabular crystals with a vitreous luster.

## Characteristics Ericlaxmanite is a rare mineral from the arsenate group, chemically a basic copper arsenate. It occurs as small, tabular or bladed crystals, often forming radial or chaotic aggregates. Its most characteristic feature is its intense, blue-green color. Crystals are usually transparent to translucent and exhibit a strong vitreous luster on their faces. ## Physical Properties This mineral is relatively soft, with a hardness of about 3.5 on the Mohs scale. It is quite brittle, which should be considered when handling specimens. The density of ericlaxmanite is significantly higher than average, at about 4.9 g/cm³, which is typical for minerals containing heavy metals like copper and arsenic. ## Colors and Varieties Ericlaxmanite occurs in a uniform, blue-green color. No color or commercial varieties have been distinguished. ## History and Name The mineral was discovered in the Tolbachik volcano area on Kamchatka, Russia, and officially described in 2015 by a team of mineralogists (I.V. Pekov et al.). The name honors Erik Laxmann (1737–1796), a Finnish-Swedish naturalist and traveler who conducted pioneering mineralogical research in Siberia and the Ural region. ## Uses Due to its extreme rarity and small crystal size, ericlaxmanite has no industrial application. It is solely an object of scientific interest and a valuable acquisition for specialized collectors of rare minerals.

Properties

Mohs hardness
3.5
Luster
Vitreous
Streak
Light green
Density
4.903
Cleavage
Perfect on {100}
Fracture
Uneven
Transparency
Transparent to translucent
Crystal system
Monoclinic

Diagnostic features

## Identification Ericlaxmanite can be identified by its characteristic blue-green color, tabular crystal habit, high density, and vitreous luster. Its origin is also key – it occurs exclusively in the specific environment of volcanic fumaroles. ## Distinguishing from Similar Minerals It can be confused with other secondary copper minerals of similar color, such as linarite, brochantite, or some turquoises. However, it is distinguished by its specific crystal form (thin tablets), higher density, and unique occurrence environment. Precise identification requires advanced analytical methods, such as Raman spectroscopy or X-ray diffraction (XRD). ## Crystal Forms It forms thin, tabular crystals with outlines ranging from rectangular to hexagonal, elongated in one direction. These crystals often combine into radial or irregular aggregates, and also form thin coatings and crusts on rocks.

Geological environment

## Genesis Ericlaxmanite is a mineral of exhalative origin. It forms as a result of the sublimation of volcanic gases in active fumarole zones, at temperatures of approximately 450-600°C. It crystallizes directly from the gas phase on the surfaces of volcanic rocks. ## Mineral Associations This mineral co-occurs with other rare arsenates and sulfates formed under similar conditions. Its typical associated minerals include johillerite, arsmirandite, hematite, tenorite, lammerite, urusovite, and alarsite, among others. ## Localities The only confirmed locality of ericlaxmanite in the world is its type locality – the "Arsenatnaya" fumarole on the second slag cone of the Northern Breakthrough of the Great Fissure Eruption of Tolbachik (1975-1976) on the Tolbachik volcano, Kamchatka, Russia.

Rarity

Very rare

For collectors

## Quality Criteria The most prized ericlaxmanite specimens are those with well-formed, sharp crystals of intense, blue-green color and strong luster. Contrast with the rock matrix and the presence of rare associated minerals are also important. Due to their small size, even well-formed microcrystals are considered valuable. ## Popular Localities The only source of specimens is the Tolbachik volcano on Kamchatka. Material from this locality is extremely difficult to obtain due to the inaccessibility of the terrain and the limited amount of material, making it highly sought after by collectors specializing in volcanic minerals or rare species.

Care and storage

## Cleaning Specimens should be cleaned only very carefully, using a soft brush to remove dust. Due to potential reactivity and arsenic content, contact with water and any chemicals should be avoided. Wet cleaning is absolutely not recommended. ## What to Avoid Avoid contact with water, acids, detergents, and other chemical agents. The mineral is sensitive to high temperatures and mechanical shocks. As an arsenate, it is toxic – avoid inhaling dust and wash hands after any contact with the specimen. ## Storage Ericlaxmanite specimens should be stored under stable conditions, in a dry place, away from direct sunlight. The safest way is to keep them in closed, padded "micromount" boxes, which protect them from physical damage and dust.

Sources

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