Читать книгу The Rare Earths: Their Occurrence, Chemistry, and Technology - Stanley Isaac Levy - Страница 39

A silico-columbate of E, Zr, Ca, Fe, Na, K; R₂Cb₂F₂SiO₉, where R represents various metals. E = 3·41; ZrO₂ = 5·7%.

Cubic, in small octahedra.

G = 3·77. H = 5¹⁄₂. Greenish brown; opaque. Metallic lustre (χαλκός = Copper, λαμπρός = lustre).

Narsarsuk, S. Greenland.