Natural History - Boxed Citrine 'Porcupine' Crystal Specimen

Each polished to expose the layers of the inner core; felt-backed. 774 grams total, 11-13.5 cm



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

Knightia alta specimen on a rectangular matrix. 168 grams, 11 cm



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

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.

From the left side lower jaw of Ursus spelaeus displaying a canine and two other teeth. 314 grams, 25 cm



From the private collection of a London gentleman.

The cave bear was a prehistoric species of bear that lived in Europe and Asia, and became extinct about 24,000 years ago during the Last Glacial Maximum.