Quartz Rock Crystal Chunk Group [100]

Comprising three egg-shaped agate specimens and one in blue calcite(?). 780 grams total, 60-68 mm



Burwell collection, Cambridgeshire, UK.

A cut and polished section of fossilised tree. 1.26 kg, 11.5 cm

Fine condition.

From the Isle of Portland, Dorset, UK. Acquired 1950s-1960s. From an old Bristol paleontological collection.

At the base of the Purbeck Formation in Dorset is a layer of rock containing fossil trees that have now been silicified. The trees grew around a saline lagoon that occupied this area towards the end of the Jurassic period. The dominant tree was a large conifer that was adapted to living in what was then a climate of hot, arid summers and warm, wet winters. The growth rings in the wood indicate that a highly seasonal environment prevailed in Southern England during the late Jurassic period. The trees were drowned by the rising waters of the lagoon and many have been preserved in their original positions of growth. At this time Dorset was situated at the same latitude as present-day Malta.

Comprising three matrices, each with a Otodus obliquus tooth. 720 grams total, 7.7-12 cm



From a Cambridgeshire, UK, collection.