Orthoquartzite

Specimens of Fault Breccia, collected from Great Langdale, Cumbria in the UK. Breccia is a term used to describe a coarse grained sedimentary rock, with large angular clasts, surrounded by a finer grained matrix. The clasts in these specimens are cemented with calcrete which is formed on calcareous materials as a result of climatic fluctuations in arid and semi arid regions. These specimens are fault breccia meaning that unlike other breccia they were formed by tectonic forces making it a tectonite. Available in multiple sizes, each specimen is supplied in a white card tray with information label.

Specimens of Purbeck Limestone, collected from the Isle of Purbeck, Dorset, in the UK. Purbeck Limestone is a fossiliferous limestone that dates from the Upper Jurassic to Lower Cretaceous period. Its deposition environment is a fresh to brackish water environment with occasional marine incursions. It’s characteristic appearance comes from densely packed shells of the freshwater snail Viviparus set in a lime mud matrix. It’s uses include construction as a building and decorative stone which is visible in Canterbury, Lincoln, Salisbury cathedrals & Westminster Abby to name but a few. These specimens are available in multiple sizes and come in a white card tray with information label.

We also supply Purbeck Limestone thin sections for microscope study which are available to buy HERE.

Specimens of Puddingstone, collected from Hertfordshire, UK. Puddingstone is a variation of conglomerate, which is term used to describe a coarse grained sedimentary rock, featuring large, well rounded clasts in a finer grained matrix. It dates back to the Paleocene to Eocene period around 56 millions years ago. This particular rock is composed almost entirely of silica and has no porosity, likely contributing to its notorious hardness. This rare rock is only found in quantity at one locality in Hertfordshire. As such, it is becoming exceedingly difficult to obtain. This rock is available in multiple sizes and each piece comes supplied in a white card tray with information label.

Specimens of Shale, collected from Yorkshire. Shale is a fine grained, clastic sedimentary rock composed of mud. This mud is a mixture of clay mineral flakes and tiny fragments of other minerals, especially quartz and calcite. Shale is characterised by thin laminae, parallel layering or bedding, less than one centimetre in thickness. This makes the rock very fissile. Shales are associated with quiet water deposition, such as in lakes, lagoons or deltas. For these specimens in particular, the depositional environment was deep water marine from the Jurassic formations of the Yorkshire coast. These specimens are available in multiple sizes and come supplied in a white card tray with information label.

We also supply Shale thin sections for microscope study which are available to buy HERE.

Specimens of Pisolite, collected from Gloucestershire, UK. Pisolites are sedimentary rocks which consist of pisoliths – concretionary grains which resemble ooids, but always more than 2mm in diameter. These pisoliths often consist of calcium carbonate, but can sometimes of rarer minerals too. These grains are approximately spherical and have concentric layers which can reach reach 10 mm in diameter. These examples date to the Mid Jurassic (Aalenian: 177 – 180Ma). Specimens are available in multiple sizes and come in a white card tray with an information label.

We also supply Pisolite thin sections for microscope study which are available to buy HERE.