What is Liottite?
Liottite is a rare six-layer cancrinite-group silicate from alkaline complexes, valued for its open framework and unusual sulfate-chloride chemistry.
Mineralogy and crystal structure
Reference formula: (Na,K,Ca)8(Al6Si6O24)(SO4,Cl)·nH2O. Liottite is a complex cancrinite-group mineral with channels and variable alkali, calcium, sulfate, chloride and water contents. Because framework chemistry and layer stacking vary, the COD model is a representative liottite structure rather than a universal composition. Liottite is classified with silicates and has a hexagonal crystal system. Typical hardness is 5–6 on the Mohs scale and specific gravity is approximately 2.5–2.7.
Colour, lustre and habit
Typical colours include white, colourless, grey, yellow, pale brown. The usual prismatic, tabular, granular habit and vitreous, pearly lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Liottite forms in or is associated with late-stage cavities in nepheline syenite and other alkaline rare-element complexes. Important documented localities include Italy, Russia, Greenland and Canada.
A rare framework from alkaline rock
Liottite rewards collectors who enjoy structure and locality. Its pale appearance hides a channelled framework and unusual anion chemistry, linking a small crystal to the late, fluid-rich stages of an alkaline complex.
Collecting and care
Protect from impact and acidic cleaners; retain the host-rock association and locality because the chemistry is part of the identification.
