Fondide

Fondide is a rare phosphate mineral described from the Fondia pegmatite belt in the northern highlands. It forms in late-stage hydrothermal veins and occurs as flat tabular crystals within granitic host rocks.

Properties: Fondide crystallizes in the monoclinic system and typically presents pale green to olive-green crystals with a vitreous to pearly luster. It has a hardness of 5.5–6 on the Mohs scale and a specific gravity around 3.2. It is commonly associated with quartz, microcline, apatite, and tourmaline.

Composition and structure: The idealized formula is (Fe2+,Mn2+)Al3+(PO4)3(OH)4, with iron, manganese and aluminum as major constituents and minor magnesium substitutions in some samples. The structure comprises phosphate tetrahedra linked by metal-oxygen octahedra, forming layered sheets.

Occurrence and geology: Fondide is known from a limited set of localities within the Fondia belt, typically occurring in vein fillings and greisen halos of granitic rocks. It forms under low-temperature, oxidizing conditions and often shows zoning.

Uses and significance: Due to its rarity, fondide has no significant economic value. It is of interest mainly to collectors and researchers studying phosphate mineralogy and crystal chemistry. Some samples display weak luminescence under ultraviolet light.

Safety and handling: There are no special hazards beyond standard mineral specimens; routine handling and dust precautions apply during mining and preparation.