Smoky quartz is a variety of quartz known for its grey to black colour, which is caused by the presence of natural traces of radium. This mineral is often used in lithotherapy because of its purifying and protective properties. Smoky quartz is also valued for its ability to promote concentration and meditation, as well as its ability to help overcome feelings of anxiety and restlessness. Due to its dark, mysterious colour, smoky quartz is also very popular in jewellery making to create elegant and timeless pieces of jewellery.