Five varieties of pyrochlore have been identified at Oka.

1. A metamict variety containing uranium and thorium; bright red color, fine-grained, associated with ijolitic rocks. a₀ = 10.43 ± 0.05 A.

2. A certain variety; chocolate-brown, coarse-grained, euhedral (octahedra and dodecahedra), associated soda pyroxene marble. G = 4.38, a₀ = 10.393 ± .001 A.

3. A thorian variety; brownish red, in calcite-forsterite rock. a₀ = 10.428 ± .005 A.

4. A zirconian variety; reddish brown to black, occurrence in carbonatite. a₀ = 10.395 ± .001 A.

5. A fifth variety is known to be high in Nb₂O₅; the complete chemical composition is not available but the Nb₂O₅ content is greater than 60%.

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