Natural History - British Specularite with Quartz Crystal Group

A trio of very large Australian amethyst crystal specimens in their natural state; in various shades of purple, including one particularly dark example. 1.5 kg total, 74-95 mm



From Australia. Mineral Imports, London, UK. Gregory, Bottley & Lloyd (Gregory's).

A Knightia alta fossil fish in matrix. 277 grams, 13 x 9.5 cm



From Wyoming, Green River Formation, U.S.A. Acquired during the 1980s. From the Pradi Collection, Boston, U.S.A.

Seasonally, some 56 million years ago, in the Green River Region of Wyoming, torrential rains fell on the mountains. The rain flowed down the mountain sides, forming wide shallow lakes in the valley below. During the dry season, these lakes evaporated (similar to certain parts of Africa today). Millions of fish died in this short period of time. This climatic cycle happened over a 20-thousand-year period. Layer upon layer of mud was deposited over these years, entombing huge numbers of fish. At a much later date volcanic activity uplifted this area to expose their fossils.

A cut and polished natural coloured banded agate mineral specimen. 331 grams, 11 cm



From Salto do Jucui, Rio Grande do Sul, Brazil. Private collection, Munster, Germany.