edingtonite

Edingtonite is a rare mineral belonging to the zeolite group. Its chemical formula is BaAl2Si3O10 · 3H2O, indicating that it is a hydrated barium aluminosilicate. Edingtonite typically forms in hydrothermal veins and cavities within igneous rocks, particularly those rich in alkali feldspar. It is often found in association with other barium-bearing minerals.

The mineral is characterized by its prismatic orthorhombic crystals, though it can also occur in massive or fibrous forms. Edingtonite is typically colorless to white, and can sometimes exhibit pale shades of yellow or pink. It has a vitreous to pearly luster and a Mohs hardness of around 3.5 to 4. One of its distinctive properties is its ability to lose and gain water without altering its crystal structure, a common characteristic of zeolites.

Edingtonite was first discovered in the 19th century and named in honor of Richard Edington, a Scottish mineral collector. While not a commercially significant mineral, it is of interest to mineralogists and geologists due to its unusual composition and occurrence. Notable localities for edingtonite include Scotland, Norway, and various sites in North America. Its rarity and specific formation conditions make it a sought-after specimen for collectors.