Hectorfloresite

Chemical formula: Na₉(I₅+O₃)(S₆+O₄)₄

Hectorfloresite is a rare, water-soluble sodium iodate-sulfate, forming colorless, prismatic crystals.

## Characteristics Hectorfloresite is a mineral from the iodate and sulfate groups, chemically defined as sodium iodate-sulfate. It occurs as small, colorless, prismatic crystals, reaching up to 0.3 mm in length. These crystals are often elongated and can form radial aggregates. Due to its water solubility, it is an unstable mineral in humid environments. ## Physical Properties This mineral is characterized by a vitreous luster. It is transparent and colorless. Its hardness and density have not been precisely determined, but it is known to be a very brittle mineral. It does not exhibit fluorescence under ultraviolet light. ## History and Name The name hectorfloresite was given in honor of Héctor Flores Williams (1907–1996), a Chilean mining engineer and professor of economic geology at the University of Chile. It was approved as a new mineral by the International Mineralogical Association (IMA) in 2017 (IMA2017-047). The discovery was made in the mine dumps of the Alianza mine, near the town of Taltal in the Antofagasta region of Chile.

Properties

Luster: Vitreous
Streak: White
Cleavage: None
Fracture: Brittle
Transparency: Transparent
Crystal system: Trigonal

Diagnostic features

## Identification The key diagnostic feature of hectorfloresite is its immediate and complete solubility in water. In field conditions, however, this is a destructive characteristic. Identification relies on analyzing its occurrence in a specific geological environment (dry nitrate deposits), its association with other rare sulfates and iodates, and its crystalline form. ## Distinguishing from Similar Minerals It can be confused with other water-soluble, colorless minerals from saltpeter deposits, such as nitratine or halite. Differentiation without advanced analytical methods (like X-ray diffraction) is practically impossible. Reaction with water is the simplest, though destructive, test. ## Crystal Forms It forms elongated, prismatic crystals with a hexagonal outline, which often occur as radial or randomly oriented aggregates.

Geological environment

## Genesis Hectorfloresite forms in extremely arid (desert) climatic conditions as a result of evaporative processes. It is a product of the weathering of nitrate deposits (Chilean saltpeter). It crystallizes directly from solutions rich in sodium, sulfates, and iodates in the oxidation zone. ## Mineral Associations This mineral occurs in association with other rare minerals characteristic of the Atacama Desert nitrate deposits. It most commonly co-occurs with nitratine, darapskite, lecontite, bloedite, and fuenzalidaite. ## Locations The only confirmed locality for hectorfloresite worldwide is its type locality – the mine dumps near the Alianza mine, north of Taltal, in the Antofagasta region of Chile.

Rarity

Extremely rare

For collectors

## Quality Criteria As a microscopic mineral, the quality of a specimen is primarily determined by the abundance and development of crystals within the aggregate. Specimens with well-formed, transparent, prismatic crystals forming radial clusters on a rock matrix are most valued. Association with other rare minerals from this locality is also important. ## Popular Localities The only known source of specimens is the type locality in Chile. Collector material comes exclusively from this single location, making it extremely rare on the market.

Care and storage

## Cleaning The mineral must absolutely not be cleaned with water or any liquids, as it is soluble in them. Mechanical cleaning is highly risky due to its brittleness. The safest way to remove dust is with a soft brush or a stream of dry air. ## What to Avoid Contact with water, water vapor, and high air humidity should be avoided, as these can quickly destroy the specimen. It should also be protected from all chemicals and sudden temperature changes. ## Storage Hectorfloresite specimens require storage in hermetically sealed containers or specialized display cases with humidity control (using a desiccant, e.g., silica gel). Storage in a dry environment is crucial for preserving the mineral.

Sources

IMA Mineral List (CNMNC)