Markascherite

Chemical formula: Cu<sup>2+</sup><sub>3</sub>Mo<sup>6+</sup>O<sub>4</sub>(OH)<sub>4</sub>

Markascherite is a very rare copper hydroxy-molybdate, forming microscopic, tabular crystals of an intense green color.

## Characteristics Markascherite is a hydrated copper molybdate, occurring as very fine, hexagonal, tabular crystals. These crystals rarely exceed 0.2 mm and typically form rosette-like or spherical aggregates, as well as thin coatings and crusts on the host rock. Due to the small size of the crystals, its macroscopic features are difficult to observe without magnification. ## Physical Properties Markascherite crystals exhibit a vitreous luster. Hardness and density have not been precisely measured due to the small size and rarity of the material. It is a transparent to translucent mineral. ## Colors and Varieties Markascherite is characterized by a vivid, emerald-green color. No color varieties or commercial varieties have been reported. ## History and Name The mineral was named in honor of Werner Markascher (born 1941), an Austrian mineral collector from Tyrol, who specialized in Alpine minerals and discovered the first specimen of this mineral. It was approved by the International Mineralogical Association (IMA) in 2011 under number 2011-061. The type locality is the tungsten ore mine in Mittersill, Felber Valley, Austria. ## Uses Markascherite has no industrial applications. It is solely of interest to collectors specializing in rare minerals (so-called "microminerals") and scientific institutions.

Properties

Luster
Vitreous
Streak
Green
Cleavage
Perfect on {0001}
Transparency
Transparent to Translucent
Crystal system
Trigonal

Diagnostic features

## Identification Identification of markascherite in the field is practically impossible. Recognition is based on observation under a microscope, where characteristic, very small, hexagonal, tabular crystals of an emerald-green color, often forming rosette-like clusters, are visible. Final confirmation requires advanced analytical methods, such as Raman spectroscopy or X-ray diffraction (XRD). ## Distinguishing from Similar Minerals Markascherite can be confused with other secondary green copper minerals, such as szenicsite, lindgrenite, or brochantite, which may co-occur in similar environments. Differentiation without specialized equipment is impossible. Key is the examination of crystal morphology under high magnification and chemical analysis to confirm the presence of molybdenum. ## Crystal Forms The mineral forms thin, tabular, hexagonal crystals. Most often, they occur as rosette-like or radial aggregates, as well as thin coatings and crusts.

Geological environment

## Genesis Markascherite is a secondary mineral, formed in the oxidation (weathering) zones of ore deposits. It forms as a result of the alteration of primary minerals containing copper and molybdenum in the presence of water and oxygen. It occurs in rock fractures and cavities. ## Mineral Associations At the type locality in Austria, markascherite co-occurs with quartz, molybdenite, scheelite, chalcopyrite, as well as other secondary molybdates such as szenicsite and lindgrenite. ## Localities The only confirmed and described locality for markascherite worldwide is its discovery site – the tungsten mine in Mittersill, Felber Valley, in the High Tauern region (Salzburg, Austria).

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of a markascherite specimen is assessed solely under a microscope. Most desirable are specimens with well-formed, sharp, undamaged crystals forming aesthetic, rosette-like aggregates. The abundance of crystals on the host rock and their intense, emerald-green color are highly valued. Contrast with a light background (e.g., quartz) also enhances visual appeal. ## Popular Localities The only source of specimens is the mine in Mittersill, Austria. Material from this locality is extremely rare and sought after by specialized collectors.

Care and storage

## Cleaning Due to the extreme delicacy and small size of the crystals, mechanical cleaning is not recommended. If absolutely necessary, compressed air can be used from a safe distance to remove dust. Avoid contact with water and any chemicals. ## What to Avoid Avoid contact with acids, bases, and any solvents. The mineral is sensitive to shocks and abrasions – even touch can destroy delicate crystal aggregates. It should not be heated or exposed to sudden temperature changes. ## Storage Specimens should be stored exclusively in specialized, sealed micromount boxes, which protect them from dust, moisture, and mechanical damage. Display is only possible under a microscope.

Sources

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