Nephelite, (K,Na)AlSiO₄

Nephelite, (K,Na)AlSiO₄, a hexagonal mineral, is often found in association with leucite. The sodium-aluminium silicate, NaAlSi₂O₈, has been prepared artificially. It is known in two forms, the hexagonal form being called soda-nephelite and the triclinic form soda-anorthite or carnegieite.