The Rare Earths: Their Occurrence, Chemistry, and Technology

by Stanley Isaac Levy

Tetragonal; very close to Zircon.

G = 3·6. H = 5¹⁄₂. Dark brown.

Kragerö, Norway.

Tengerite.

Hydrated carbonate of E, Be, Ca, etc.; a weathered [Gadolinite] (q.v.). E₂O₃ = 39·2-47·8%.

Amorphous.

White; opaque; very soft.

Llano Co., Texas.

Thalenite.

H₂E₄Si₄O₁₅, with traces of Fe´´´ and Al. Yttr = 58·6-63·9%.