Falottaite
Chemical formula: Mn²⁺(C₂)⁶⁺O₄·3H₂O
Falottaite is an extremely rare, water-soluble manganese oxalate, forming tiny, acicular crystals of a straw-yellow color.
Properties
- Mohs hardness
- 2.5
- Color
- Colorless
- Luster
- Silky
- Streak
- White
- Density
- 1.924
- Transparency
- Transparent
- Crystal system
- Orthorhombic
Diagnostic features
## Identification Characteristic features of falottaite include its straw-yellow color, acicular or hair-like crystal form creating radial or felt-like aggregates, and its extreme rarity. A key diagnostic feature is its water solubility. ## Distinguishing from Similar Minerals It can be confused with other secondary minerals of similar appearance, such as some sulfates or arsenates. However, its genesis in manganese deposits, co-occurrence with other oxalates (like lindbergite), and the water solubility test allow for its unambiguous differentiation. ## Crystal Forms Falottaite forms very fine, acicular or hair-like crystals that combine into radial, star-like aggregates or tangled, felt-like masses.
Geological environment
## Genesis It is a secondary mineral, formed as a result of hydrothermal processes or weathering within manganese ore deposits. Its formation is linked to the interaction of solutions rich in oxalic acid (of organic origin, e.g., from lichen decomposition) with manganese minerals. ## Mineral Associations Falottaite co-occurs with other manganese minerals and oxalates. In its type locality (Monte Alpe), it was found in association with braunite, cryptomelane, pyrochroite, rhodochrosite, and especially another oxalate – lindbergite. ## Localities The only confirmed occurrence of falottaite in the world is its type locality: the Monte Alpe manganese ore mine, located in the municipality of Maissana, La Spezia province, Liguria, Italy.
Rarity
Extremely rare
For collectors
## Quality Criteria The quality of falottaite specimens is assessed based on the richness and aesthetics of the crystal aggregates. Most valued are samples with well-formed, radial clusters of acicular crystals, contrasting with the dark host rock. Due to the microscopic nature of the mineral, the quality of the specimen under magnification is crucial. ## Popular Localities The only source of specimens is the Monte Alpe mine in Italy. Material from this locality is extremely difficult to obtain and appears on the collector's market sporadically, mainly circulating among micromineral specialists.
Care and storage
## Cleaning The mineral must absolutely not be wet-cleaned, as it is water-soluble. Specimens should only be cleaned with compressed air from a safe distance, using minimal pressure to avoid damaging the fragile crystals. ## What to Avoid Avoid all contact with water, cleaning solutions, and chemicals. The mineral is very sensitive to moisture and should therefore be protected from humid air. It is also very mechanically delicate. ## Storage Falottaite specimens must be stored in sealed, dry containers, preferably with a desiccant (e.g., silica gel). "Micromount" boxes are recommended to protect delicate crystals from physical damage and dust.