Mesosiderites are a class of stony-iron meteorites consisting of about equal parts of metallic nickeliron and silicate. They are breccias with an irregular texture, silicates and metal occur often in lumps or pebbles, as well as in fine-grained intergrowths. The silicate part contains olivine, pyroxenes and Ca-rich feldspar, and is similar in composition to eucrites and diogenites.