Summary: A small specimen at first thought to be natrolite has proved to be a new mineral, for which the name rhodesite is proposed; it is fibrous, with α 1·502, β 1·506, γ 1·515, elongation γ, extinction straight, sp. gr. 2·36. The composition is near 4(Ca,Na2,K2)O. 10SiO2. 7H2O, and the water is all zeolitic.