Okenite

Okenite is a rare, white, fibrous mineral composed of hydrated calcium silicate. Its chemical formula is Ca₁₀Si₆O₁₅(OH)₂·7H₂O. It typically forms in cavities within basaltic rocks, often associated with other zeolites and minerals like apophyllite and prehnite. Okenite is characterized by its soft, woolly or cotton-like appearance, which can sometimes be mistaken for organic material. It is found in various locations worldwide, including India, the Czech Republic, Iceland, and the Faroe Islands. The mineral was named in honor of Lorenz Oken, a German naturalist. While not a commercially significant mineral, okenite is of interest to mineral collectors due to its unique texture and aesthetic appeal. It is relatively fragile and can dissolve in dilute acids.