Carnelian (also pronounced as cornelian) is a brownish-red crystal commonly used as a semi-precious gemstone. Similar to the carnelian is sard, which is commonly more laborious and darker (the distinction is not rigidly determined, and the two names are often used conversely). Both carnelian and sard are qualities of the silica mineral chalcedony colored by impurities of iron oxide. The color can range considerably, ranging from pale orange to an extreme almost-black coloration. It is most commonly found in Indonesia, Brazil, India, Russia (Siberia), and Germany.