Gadolinite is a rare mineral primarily composed of cerium, iron, silicon, and oxygen. It is known for its dark color, which can range from black to brown, and its glassy luster. Gadolinite is often found in granitic rocks and is named after the Swedish chemist Johan Gadolin, who contributed to the study of rare earth elements. This mineral is significant because it contains several rare earth elements, including yttrium and neodymium. These elements are essential in various high-tech applications, such as electronics, magnets, and catalysts. Gadolinite is typically mined for its valuable components, making it an important resource in modern technology.