Greenschist thin section microscope slides from North Wales exhibiting the minerals that give this rock its green colouration, serpentine and chlorite. The thin sections also display platy minerals such as muscovite mica. Greenschist is a metamorphic rock which are often produced in low temperature and pressure environments by regional metamorphism. The colouration is due to the high content of green mineral present in the rock, such as chlorite, serpentine, and epidote where as minerals such as muscovite mica give the rock its foliation. Each section is made to 30 microns thickness and the glass is 46 x 27 mm, ideal for microscopy and educational purposes.