A meteorite composed of nickel–iron and silicate minerals in roughly equal proportions; also known as a siderolite. Such meteorites were apparently formed within asteroid-sized parent bodies. Stony-iron meteorites comprise only about 1% of observed falls. Four groups of stony-iron meteorites have been defined, the two main ones being the pallasites and mesosiderites. The other two, the lodranites and siderophyres, are extremely rare.