Albertiniite

Chemical formula: Fe₂+(S₄+O₃)·₃H₂O

Albertiniite is an extremely rare iron sulfite, forming delicate, acicular crystals of a pale green color.

## Characteristics Albertiniite is a hydrated iron sulfite, occurring as extremely delicate, tiny crystals. Typical specimens form radial aggregates or small bundles composed of acicular, elongated crystals. Its color is usually pale green to greenish-white. Due to the small size of the crystals, it is a mineral primarily found as micromounts. ## Physical Properties Albertiniite crystals are transparent and characterized by a vitreous luster. This mineral is very soft and brittle. Its density, calculated based on the chemical formula and unit cell parameters, is approximately 2.25 g/cm³. ## Colors and Varieties This mineral occurs in a uniform, pale green or greenish-white color. No color varieties or commercial varieties are known. ## History and Name Albertiniite was officially recognized as a new mineral species by the International Mineralogical Association (IMA) in 2011. Its name honors Dr. Alberto Albertini (born 1942), an Italian collector and researcher, for his contributions to the study of the mineralogy of the Cetine di Cotorniano mine in Italy, which is also the type locality of this mineral. ## Uses Due to its extreme rarity and instability, albertiniite has no practical applications. It is solely an object of scientific and collecting interest for specialized collectors of rare minerals.

Properties

Luster: Vitreous
Streak: White
Density: 2.25
Cleavage: Perfect on {010}
Transparency: Transparent
Crystal system: Monoclinic

Diagnostic features

## Identification The characteristic features of albertiniite are its form – radial aggregates of thin, acicular crystals – and its pale green color. A key diagnostic clue is its extreme instability in contact with air and moisture. Definitive identification is only possible using advanced analytical methods, such as X-ray diffraction (XRD). ## Distinguishing from Similar Minerals Albertiniite may be confused with other secondary, acicular iron minerals, such as melanterite. However, melanterite is a sulfate, not a sulfite, and although also sensitive to moisture, it is much more stable and common than albertiniite. Differentiation from other rare sulfites from the same locality requires specialized studies. ## Crystal Forms This mineral exclusively forms acicular or fibrous crystals, which combine into radial, stellate, or chaotic aggregates.

Geological environment

## Genesis Albertiniite is a secondary mineral, forming under specific conditions in a post-mining environment. It forms as a result of pyrite oxidation with very limited oxygen access. Its genesis is associated with the activity of mine waters in old, abandoned workings. ## Mineral Associations This mineral occurs in association with gypsum, native sulfur, pyrite, and other rare secondary minerals characteristic of the type locality. ## Localities The only known occurrence of albertiniite in the world is its type locality – the Cetine di Cotorniano mine, near Chiusdino in the province of Siena, Tuscany, Italy.

Rarity

Extremely rare

For collectors

## Quality Criteria The quality of albertiniite specimens, which are almost exclusively micromounts, is assessed based on the size and richness of the crystal aggregates. Specimens with clearly formed, radial bundles of acicular crystals, deposited on a contrasting matrix, are most valued. Due to its rarity, any well-identified specimen is valuable. ## Popular Localities The only source of albertiniite specimens is its discovery site – the Cetine di Cotorniano mine in Italy. This mineral is not known from any other locality in the world.

Care and storage

## Cleaning Albertiniite specimens are extremely sensitive to moisture and should not be cleaned with water or any other liquids. The only safe method is very careful dust removal using a soft brush or a low-pressure stream of compressed air. ## What to Avoid Contact with water and moisture must be strictly avoided, as the mineral readily dissolves and undergoes chemical alteration. It is also very unstable in contact with atmospheric oxygen, under which it oxidizes to iron sulfates. It should be protected from high temperatures and direct sunlight. ## Storage Albertiniite requires storage under special conditions. It is best placed in a sealed, airtight container (e.g., a "perky box") along with a desiccant, such as silica gel. Store in a dark, cool place with a stable temperature.

Sources

IMA Mineral List (CNMNC)