One of the most spectacular discoveries made by the Geological Society "Spirifer" was the finding of excessiv calcite twins in 2001, quality of which was similar to the best world specimens  - video film documentation available.

All specimens are from the Geological Society "Spirifer" collection.

All photos by Jeff Scovill (www.scovilphoto.com).

Calcite - multiply twinned, size 4.5 cm. Sambava, Northern Madagascar.

Calcite - multiply twinned on quartz, size 5.5 cm. Sambava, Northern Madagascar.

Calcite - multiply twinned on quartz, size 4 cm. Sambava, Northern Madagascar.

Calcite - multiply twinned on quartz, size 4.5 cm. Sambava, Northern Madagascar.

Calcite - multiply twinned, two generations, size 7 cm. Sambava, Northern Madagascar.

Calcite - multiply twinned, size 8.5 cm. Sambava, Northern Madagascar.

Calcite - multiply twinned, size 7 cm. Sambava, Northern Madagascar.