Mantle composition refers to the elements and minerals that make up the Earth's mantle, which is the layer located between the crust and the core. The mantle is predominantly composed of silicate minerals, with the most abundant elements being oxygen, silicon, magnesium, and iron. Scientists study mantle composition to understand the processes that control the Earth's interior dynamics, such as mantle convection and plate tectonics. This research area also sheds light on the origins of different rock types, volcanic activity, and the formation of minerals and gemstones. Techniques such as seismic imaging, geochemical analysis, and experimental petrology are used to investigate mantle composition.