Purple Amethyst Crystal Geode Specimen Group [20]

Irregular geode matrix with light purple amethyst crystals; the metal branches tipped with polished light-coloured citrine pebbles. 479 grams, 20 cm



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

Comprising two triangular pieces, cut and polished on several sides, probably recycled material mined in ancient Roman times between the 1st and 5th centuries A.D. 195 grams total, 56-58 mm



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

Mons Porphyrites (today Jabal Abu Dukhkhan) is the mountainous site of a group of ancient quarries in the Red Sea Hills of the inhospitable eastern desert in Egypt, a five-day trip from the Nile during Roman times. They were discovered by Caius Cominus Leugas in 18 A.D., and during the Roman Empire, the mines officially belonged to the emperor and were the only known source of the Imperial Porphyry, Mons Porphyrites. This dark purple stone was associated with royalty and used for prestigious sculpture and architecture. The location of the mines was lost sometime in the 5th century and rediscovered in the early 19th century. Excavations in the area have revealed the well-preserved quarries and the dwelling places of the quarrymen, and also thousands of ostraca have been discovered containing messages that provide details of how the quarrying took place, and of how the highly skilled quarrymen ordered their food.

A Knightia alta fish on a rectangular limestone matrix. 589 grams, 17.8 cm



From a Cambridgeshire, 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.