Natural History - Boxed Icelandic Spar Specimen Group [20]

The Knightia alta specimen on a rectangular sandstone matrix. 140 grams, 10 cm



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 nugget with metallic lustre; supplied in a display box. 235 grams total, 58 mm



From Great Rock mine, Devon, UK. Collected in person in 1964. 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.

The mineral was an important ingredient in the rust-resistant paint used on Royal Navy ships and bridges. Shiny ore has also been used in glaze for pottery, decorative bricks and tiles giving it a sparkly finish.

With one polished side showing grey and white banding and an internal cavity with quartz crystals. 1.48 kg total, 26-26.5 cm



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