Hornfels thin section microscope slide exhibiting a dark colour and a characteristic none crystalline form. Fine grains fit together like the fragments of a mosaic, this is often referred to as rough pavement or pavement structure. Larger quartz clasts are visible but these have recrystallised to form a fine, interlocking mosaic of quartz within the original grain cast. Hornfels forms by contact metamorphism and as such the rock is not foliated due to the absence of pressure thus the thin sections show no grain fabric. They are often derived from original rocks such as sandstone, shale, slate, limestone and so on. This particular material was collected by staff from Shap quarry, Cumbria. Each section is made to 30 microns thickness and the glass is 46 x 27 mm in size with a cover slip. Supplied in a protective card sleeve with a label, ideal for microscopy and educational purposes.