Footemineite

Chemical formula: Ca₂Mn²⁺₅Be₄(PO₄)₆(OH)₄·6H₂O

Footemineite is a rare, yellow mineral from the roscherite group, being a hydrated calcium, manganese, and beryllium phosphate.

## Characteristics Footemineite is a rare phosphate mineral from the roscherite group. It forms transparent crystals with a characteristic yellow color. It usually occurs as small, tabular or bladed crystals, often gathered in radial or rosette aggregates. It is valued by collectors for its rarity and attractive appearance. ## Physical Properties Footemineite crystals have a hardness in the range of 4.5-5 on the Mohs scale. They have a vitreous luster and a white streak. They are transparent. Due to the small size of the crystals, precise determination of density is difficult. ## Colors and Varieties This mineral occurs in shades of yellow. No distinct color or commercial varieties have been identified. ## History and Name Footemineite was described as a new mineral in 1998. Its name honors the American company Foote Mineral Company, which managed the Foote Lithium Co. Mine in Kings Mountain, North Carolina (USA) – this is the discovery site (type locality) of this mineral. ## Uses Footemineite has no industrial application. It is solely an object of interest for collectors and scientists.

Properties

Mohs hardness
4.5-5
Luster
Vitreous
Streak
White
Density
0
Cleavage
Good on <mi>{0_11} and {100}</mi>
Transparency
Transparent
Crystal system
Triclinic

Diagnostic features

## Identification Footemineite can be identified by its characteristic yellow color, tabular crystal habit, and occurrence in radial aggregates. Good cleavage in two directions is also a helpful identification feature. ## Distinguishing from Similar Minerals It can be confused with other minerals from the roscherite group, such as roscherite or zanazziite. Final differentiation requires advanced chemical analyses (EDS) or X-ray analyses (XRD) to confirm the composition, especially the dominance of calcium and manganese. ## Crystal Forms Crystals are usually small, with a tabular or bladed habit, often flattened. They form characteristic, radial or rosette clusters and aggregates, growing on the surface of the host rock.

Geological environment

## Genesis Footemineite is a hydrothermal mineral. It forms in the late stages of crystallization of complex, lithium- and phosphorus-rich granitic pegmatites. It crystallizes in rock fissures and vugs. ## Mineral Associations This mineral co-occurs with other phosphates, such as montgomeryite, strengite, rockbridgeite, as well as with quartz, microcline, and albite. ## Localities The most important and only confirmed locality for footemineite is its type locality – the Foote Lithium Co. Mine in Kings Mountain, Cleveland County, North Carolina, USA.

Rarity

Very rare

For collectors

## Quality Criteria The most prized footemineite specimens are those with well-formed, sharp crystals forming aesthetic, radial aggregates. The intensity and purity of the yellow color also increase the value of the specimen. Contrast with the host rock matrix, on which the crystals grow, is important. ## Popular Localities The only source of collector specimens is the Foote Lithium Co. Mine in North Carolina, USA. Material from this locality is highly sought after by collectors specializing in rare minerals and pegmatite minerals.

Care and storage

## Cleaning Specimens should be cleaned very carefully, using a soft brush to remove dust. If necessary, distilled water can be used, but prolonged soaking should be avoided. Always ensure the specimen is completely dry before storing. ## What to Avoid Avoid contact with acids and other chemicals that can damage the mineral. Footemineite is relatively soft, so it must be protected from scratching by harder minerals. It should not be heated or subjected to sudden temperature changes. ## Storage It is recommended to store specimens in separate, padded boxes to prevent abrasion and mechanical damage. Protect them from dust and direct, prolonged sunlight.

External references

Sources

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