£1.00 – £2.74
Slate from Wales, famous for its use as a roofing material, these specimens exhibit text book characteristics such as fine grain crystal structure, foliation, slatey cleavage and a variety of colours, excellent for educational use, supplied in various sizes.
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from a shale (or similar) protoliths composed of clay or volcanic ash through low grade regional metamorphism. It is the finest grained foliated metamorphic rock which one can encounter, foliation may not correspond to the original sedimentary layering, but instead is in planes perpendicular to the direction of compression. Many people know of slat, due to its numerous uses in the building and architectural industry, especially due to the fact that it has long been used as roofing material in most European countries. This Cambrian slate from North Wales can be found in many shades of grey, from pale to dark, and may also be purple, green or cyan, specimens are supplied in labelled card trays and are available in various sizes to choose from.