Jaspers are an opaque variety of chalcedony, a microcrystalline form of quartz (SiO₂), known for their diverse colors and intricate patterns caused by mineral impurities such as iron, clay, and organic materials. They have a Mohs hardness of 6.5 to 7, making them durable for jewelry and carvings. Jasper forms in sedimentary and volcanic environments, often displaying unique banding, spots, or swirls. Common types include Red Jasper, Picture Jasper, Ocean Jasper, and Brecciated Jasper. Major sources include Brazil, Madagascar, India, the United States, and Russia.