Because most of them are the remains of the crust and mantle of asteroids, they greatly resemble ordinary terrestrial rocks. Stony meteorites contain too little of the nickel-iron alloy that characterizes iron meteorites to register with a metal detector, a favorite tool of meteorite hunters. However, most will cause a magnet hung from a string to swing toward them, and this is one of the first tests a meteorite hunter will employ once they've found a likely specimen.
A few stony meteorites are thought to have originated on larger celestial bodies, such as the Moon and Mars. One specimen in particular, found in Antarctica in 1987, is believed by some scientists to show traces of ancient life on Mars! You can find more information on this controversy, as well as many other interesting facts about meteorites, in O. Richard Norton's book, Rocks from Space.
Because of the difficulty of finding them, stony meteorites are less available on the market than are the nickel-iron specimens. We are very pleased to be able to add stony meteorites to our product offerings, in a wide range of sizes and prices.