A Carcharocles megalodon shark tooth, with some serrations and good polished tooth enamel. 76 grams, 94 mm



Found Wrightsville Beach, North Carolina. Ex The Fossil Exchange. From a private Tyneside collection, formed since the early 2000s. Accompanied by a Fossil Exchange information card.

Carcharodon megalodon is regarded as one of the largest and most powerful marine predators in vertebrate history and likely had a profound impact on structuring of the marine communities. Fossil remains indicate that this giant shark reached a length of more than 16 metres (52 ft) and also affirm that it had a cosmopolitan distribution. Scientists suggest that in life it looked like a stockier version of the great white shark, Carcharodon carcharias.

Comprising ten variously shaped geode halves, each with an exposed internal cavity. 1.07 kg total, 49-80 mm



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

Cleoniceras sp. specimen cut in two halves to reveal the internal crystal lined chambers, polished throughout. 650 grams total, 15 cm each



From Madagascar. Ex Lincolnshire, UK, collection.

A cut section of a geode lined with well-formed amethyst crystals with calcite. 2.68 kg, 23.5 cm



From the private collection of author and historian Dr DeWitt Bailey, one of the global authorities on the confederate army in the US civil war; thence by descent to his grandson.

A layered specimen of white barite crystals. 864 grams, 14.5 cm



From Settlinstones Mine, Newbrough, Northumberland, UK. De-acquisitioned from a private Cornwall, UK, collection.)

A triangular section with deep-coloured prismatic crystals. 543 grams, 11.2 cm



From Brazil. From a Lincolnshire, UK, collection.

Cut section of a botryoidal boulder. 1.87 kg, 17.4 cm



From Democratic Republic of the Congo, Central Africa. Ex Mineral Imports, London, UK. Gregory, Bottley & Lloyd (Gregory's), Harwich, UK.

A composite nodules lined with dyed vibrant pink quartz crystals. 120 grams total, 53-58 mm



Ex Cambridgeshire, UK, collection.

A cut section with brown quartz on fluorite. 1.56 kg, 15.5 cm



From Cacilia Mine, Wolsendorf, Bavaria, Germany. De-acquisitioned from a private Cornwall, UK, collection.

Comprising three rounded geodes. 452 grams total, 47-86 mm



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

An Otodus obliquus tooth made into a pendant and suspended from a cord necklace. 8.77 grams total, tooth: 34 mm



Ex Cambridgeshire, UK, collection.

The aquatic arthropod showing good detail to the carapace, resting on an irregular matrix. 211 grams, 77 mm



From Morocco, North Africa. From a Cambridgeshire, UK, collection.