Halilsarpite

Q: How to identify Halilsarpite?

## Identification Identification of halilsarpite is possible only through advanced analytical methods, such as Raman spectroscopy and chemical analysis using an electron microprobe (EDS/WDS). Visually, in the field or in a collection, it is practically impossible to distinguish from other microscopic, secondary arsenic minerals of similar color. ## Distinguishing from Similar Minerals It can be confused with many other rare arsenates found in Cap Garonne, such as geminite, lavendulan, mahnertite, or capgaronnite. A characteristic feature, visible under high magnification, is its tabular crysta

Q: Where does this mineral come from Halilsarpite?

## Genesis Halilsarpite is a secondary mineral that forms in the oxidation zone (gossan) of polymetallic deposits rich in arsenic. It forms as a result of the weathering of primary sulfides, mainly tennantite, in the presence of dolomitic rocks. It forms under low-temperature conditions, in voids and fissures of the rock. ## Mineral Associations This mineral co-occurs with other rare arsenates and

Q: How to care for Halilsarpite?

## Cleaning Halilsarpite specimens, due to their extreme rarity and microscopic size, should not be cleaned mechanically or chemically. Any attempts at cleaning may irreversibly damage the delicate crystals. If dust removal is necessary, it can be done very carefully with a soft brush or a photographic air blower. ## What to Avoid Avoid contact with water, acids, detergents, and any other chemicals. The mineral is likely sensitive to changes in temperature and humidity. It should not be heated o

Chemical formula: [Mg(H₂O)₆][CaAs₃+₂(Fe₃+₂.₆₇Mo₆+₀.₃₃)(As₅+O₄)₂O₇]

Halilsarpite is an extremely rare, hydrated calcium, iron, magnesium, and molybdenum arsenate, forming microscopic, tabular crystals of a yellowish-brown color.

## Characteristics Halilsarpite is a mineral from the arsenate group, distinguished by its very complex chemical composition. It occurs as extremely small, tabular or bladed crystals, reaching sizes up to 0.2 mm. These crystals are transparent to translucent and are characterized by a yellowish-brown color and a vitreous luster. They typically form small, scattered aggregates or appear as individual crystals on the surface of the host rock. ## Physical Properties Due to the microscopic size of the crystals, most of halilsarpite's physical properties have not been precisely determined. Its hardness is too low to scratch calcite (below 3 on the Mohs scale). Density has also not been measured, but only calculated based on its chemical composition and unit cell parameters, and is approximately 3.25 g/cm³. ## History and Name The mineral was approved by the International Mineralogical Association (IMA) in 2018 under number 2018-063. Its name honors Halil Sarp (born 1946), a Turkish mineralogist and crystallographer from the Natural History Museum in Geneva, for his contributions to the discovery and description of many new minerals, especially from the arsenate group. The discovery was made on samples originating from the historic Cap Garonne mine in France. ## Uses Halilsarpite has no industrial applications. Its significance is purely scientific and collectible, as a unique and very rare representative of complex arsenates.

Properties

Mohs hardness: <3
Luster: Vitreous
Streak: Light yellow
Density: 3.25
Cleavage: Perfect on {010}
Fracture: Uneven
Transparency: Transparent to translucent
Crystal system: Triclinic

Diagnostic features

## Identification Identification of halilsarpite is possible only through advanced analytical methods, such as Raman spectroscopy and chemical analysis using an electron microprobe (EDS/WDS). Visually, in the field or in a collection, it is practically impossible to distinguish from other microscopic, secondary arsenic minerals of similar color. ## Distinguishing from Similar Minerals It can be confused with many other rare arsenates found in Cap Garonne, such as geminite, lavendulan, mahnertite, or capgaronnite. A characteristic feature, visible under high magnification, is its tabular crystal habit. However, definitive differentiation requires specialized laboratory equipment. ## Crystal Forms Halilsarpite crystallizes in the form of very small, thin, tabular crystals, often with a hexagonal or rhombic outline. These crystals can form small, loose aggregates or occur individually.

Geological environment

## Genesis Halilsarpite is a secondary mineral that forms in the oxidation zone (gossan) of polymetallic deposits rich in arsenic. It forms as a result of the weathering of primary sulfides, mainly tennantite, in the presence of dolomitic rocks. It forms under low-temperature conditions, in voids and fissures of the rock. ## Mineral Associations This mineral co-occurs with other rare arsenates and sulfates. In its type locality (Cap Garonne), it was found in association with tennantite, kankite, geminite, ludlockite, olivenite, mahnertite, lavendulan, gypsum, and quartz. ## Localities The only confirmed occurrence of halilsarpite in the world is its type locality – the Cap Garonne mine, Le Pradet, near Toulon in the Var department, in the Provence-Alpes-Côte d'Azur region of France. This is a historic site known for the occurrence of many unique secondary minerals.

Rarity

Extremely rare

For collectors

## Quality Criteria As a microscopic mineral, the main criterion for evaluating a specimen is the quality and abundance of crystals visible under the microscope. Most valued are samples with numerous, well-formed, sharply terminated crystals of intense color, set against a contrasting background of the host rock. Association with other rare minerals from this locality is also important.

Care and storage

## Cleaning Halilsarpite specimens, due to their extreme rarity and microscopic size, should not be cleaned mechanically or chemically. Any attempts at cleaning may irreversibly damage the delicate crystals. If dust removal is necessary, it can be done very carefully with a soft brush or a photographic air blower. ## What to Avoid Avoid contact with water, acids, detergents, and any other chemicals. The mineral is likely sensitive to changes in temperature and humidity. It should not be heated or exposed to direct sunlight. ## Storage Specimens should be stored exclusively in specialized, sealed "micromount" boxes that protect them from dust, mechanical damage, and humidity changes. Display should only take place under controlled conditions, preferably under a microscope.

Sources

IMA Mineral List (CNMNC)