What is Leucophanite?
Leucophanite is a rare beryllium-bearing silicate of alkaline complexes, recognised by pale colour and its link to unusual rare-element mineralogy.
Mineralogy and crystal structure
Reference formula: CaNaBeSi2O6F. Leucophanite is an orthorhombic beryllium silicate fluoride with variable rare-earth substitution. The selected COD structure represents the leucophanite framework; natural compositions can vary, so the host complex and analytical data should remain with the specimen. Leucophanite is classified with silicates and has a orthorhombic crystal system. Typical hardness is 5.5–6 on the Mohs scale and specific gravity is approximately 2.8–3.0.
Colour, lustre and habit
Typical colours include white, colourless, yellow, pale green. The usual prismatic, granular, massive habit and vitreous, pearly lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Leucophanite forms in or is associated with alkaline nepheline-syenite complexes and late-stage cavities in rare-element rocks. Important documented localities include Greenland, Norway, Russia, Canada and Sweden.
Pale colour, uncommon chemistry
Leucophanite appeals to collectors who look beyond bright colour. Its understated crystals come from some of the world's most chemically unusual alkaline complexes, where beryllium, fluorine and rare-earth elements produce remarkable mineral diversity.
Collecting and care
Protect crystals from impact and acidic cleaners; beryllium-bearing material should not be cut or ground without professional controls.
