Large Boxed Pyrite Crystal Paperweight Mineral Specimen

An oval matrix with a Knightia alta specimen. 81 grams, 96 mm



From Wyoming (Green River Formation), USA. 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.

Comprising variously sized chunks displaying good lustre. 2.69 kg total, 31-62 mm



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

From Mammuthus Primigenius showing curvature and the inside structure. 502 grams, 37.5 cm



From Latton Gravels, Wiltshire, UK. Acquired from Milton Keynes Geological Society in 1999. From the private collection of Kenneth Machin (1936-2020), Buckinghamshire, UK; with collection no.VM99; his collection of antiquities and natural history was formed since 1948; thence by descent.