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A Titanosilicate of Fe´´ and Na, with small proportions of Fe´´´ and Al´´´. Closely allied to the amphiboles. TiO₂ = 7-8%.

Anorthic. Habit prismatic.

G = 3·80-3·86. H = 5¹⁄₂. Black; pleochroism strong.

Greenland and S. Norway.