A polished underside of a geode containing upward-reaching stalagmites covered in druzy brown quartz and small, sparkling white quartz crystals; mounted on a custom-made display stand. 6 kg, 15 x 30 x 17cm, 20 cm including stand



From Artigas, Uruguay. Property of a London lady.

Composite nodule with enhanced green crystals. 115 grams total, 53-56 mm



From a Cambridgeshire, UK, collection.

Group of fourteen pyramidal points. 2.88 kg total, 58-84 mm



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

Boxed group of cut agate geodes, most with crystal-lined cavities, and pale-blue calcite specimens. 1.85 kg total, 29-52 mm



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

Cluster of hopper crystals exhibiting a stairstep crystal structure and iridescent colours. 15 grams, 33 mm



From a Cambridgeshire, UK, collection.

Two irregular slabs showing typical purple, blue and white banding. 935 grams total, 25.1-25.6 cm



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

A Carcharocles megalodon shark tooth, with serrations and polished tooth enamel. 351 grams, 14.5 cm



From a Lincolnshire, UK, collection.

Carcharodon megalodon is regarded as one of the largest and most powerful marine predators in vertebrate history and likely had a profound impact on the 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 various bones and jaw fragments with partial teeth, a coprolite, and others, each with an inked collector's number. 1.85 kg total, 33-99 mm



From the private collection of Kenneth Machin (1936-2020), Buckinghamshire, UK; his collection of antiquities and natural history was formed since 1948; thence by descent.

The Mosasaur is an extinct, large marine reptile dinosaur with an elongated body, long snout and paddle-like limbs. Found worldwide, they competed with other well-known sea predators of the Late Cretaceous, such as plesiosaurs and ichthyosaurs, for food, existing primarily on a diet of ammonoids, cuttlefish and fish.

Showing prominent ribbing and some iridescence. 167 grams, 71 mm



From the private collection of Kenneth Machin (1936-2020), Buckinghamshire, UK; his collection of antiquities and natural history was formed since 1948; thence by descent.

A nickel-iron meteorite (IAB) with a suspension loop and cord for wearing. 6.21 grams, pendant: 28 mm



From a Cambridgeshire, UK, collection.

A crater field of roughly 26 craters was found in the vicinity of this crater, which is estimated to date to 4-5 thousand years BP. The age of the meteorite itself is thought to be c.4.5 billion years, formed as part of the development of this solar system. The largest two fragments, the 30.8-ton Gancedo and 28.8-ton El Chaco, are among the heaviest meteorite masses ever recovered on Earth. In 1576, the governor of a province in Northern Argentina commissioned the military to search for a large mass of iron, which it was believed the local people claimed had fallen from the sky and which they used for their weapon production. The expedition discovered a large mass of metal, which was assumed to be an iron mine, and brought back a few samples, which were described as being of unusual purity. Following the legends, in 1774, Don Bartolomé Francisco de Maguna rediscovered the iron mass. He himself did not believe that the stone had fallen from the sky and assumed that it had formed by a volcanic eruption. However, he sent the samples to the Royal Society of London. In 199,0 it became protected by law.

Large collection of shark teeth, including Odontapsis, Lamna oblirua, Charcharodon auriculatus, Striatolamia, and others; most with an inked collector's number or a numbered sticker. 973 grams total, 30.5 x 24 cm including box



From the private collection of Kenneth Machin (1936-2020), Buckinghamshire, UK; his collection of antiquities and natural history was formed since 1948; thence by descent. Accompanied by a list with collection numbers describing each species, dates, and provenances.

Comprising twenty-eight specimens of small intergrown pyrite crystals, some with characteristic striations. 2.56 kg total, 37-67 mm



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