Greisen metamorphic rock specimens from Caldbeck Fells, Cumbria, composed mainly of quartz and mica with an off yellow colouration. The rock is known as an endoskarn and forms when hydrothermal fluid and heat alter a granitic body, resulting a heavily altered rock which may contain trace amounts of rare elements. These samples are suitable for advanced collectors and higher level education and are available in three sizes, each pieces will come supplied in a card tray with a label.
Eocene puddingstone conglomerate collected from Hertfordshire, UK. Puddingstone is a textbook a variety of conglomerate, it is composed almost entirely of silica; the smooth and rounded silicic pebbles are held firmly in place by a hard silica cement. Available by weight, supplied in a 1kg bag with an information label.