Natural History - Fossil Dicranurus Monstrosus Trilobite

Comprising large irregular chunks of pale green chrome mica. 3.55 kg total, 10.6-15.5 cm



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

Comprising three rounded sandstone matrices, each with a Knightia alta specimen. 159 grams total, 75 mm each



From a Lincolnshire, UK, collection.

In southwest Wyoming (and parts of Colorado and Utah) in the Green River Formation are found some of the world's most outstanding specimens of fossil fish. The Green River system was composed of three lakes: Lake Ulinta, Lake Gosiute and Fossil Lake. These Eocene lakes lay in a series of intermountain basins formed by geological events that uplifted the Rocky Mountains during the early Tertiary time. The climate was much different from the desert-like climate of this area today. Both the fauna (crocodiles, alligators, boa constrictors and some subtropical fish families) and the flora (such as large palm trees) indicate a climate much like that found along the Gulf Coast today. Large amounts of ash found in the sediments indicate that volcanoes were particularly active at this time.

the large pebble with iridescent dark purple surfaces with small areas of blue and brown. 189 grams, 54 mm



Collected in person from various parts of the world mainly between 1957-1966. From the private mineral collection of Stephen Atkinson, Harpenden, UK. Accompanied by a copy of a letter from the vendor giving details of him collecting these minerals throughout his life.