Is a meteorite heavy for its size?
Usually, yes: most stony meteorites are denser than common rocks because they contain iron-nickel metal, and iron meteorites are more than twice as heavy as an ordinary stone of the same size. Some carbon-rich meteorites, though, are surprisingly light.
Meteorite hunters often say a real meteorite feels heavy in the hand, and there is a good reason. Density is how much mass is packed into a given volume. Common Earth rocks at the surface, such as granite, sandstone and limestone, have densities of about 2.5 to 2.8 grams per cubic centimetre. Ordinary chondrites, the commonest meteorites, are typically about 3.2 to 3.5, because they contain metal and dense iron-rich minerals. So a chondrite feels noticeably weightier than a garden stone of the same size.
Iron meteorites are in another league. Their iron-nickel metal has a density close to 8 grams per cubic centimetre, about three times that of typical crustal rock. Lift a fist-sized iron and it feels like a lump of solid steel, which in a sense it is. Pallasites, a mixture of metal and green olivine crystals, fall in between.
Not all meteorites follow the rule. Some achondrites, such as eucrites from the asteroid Vesta, are only a little denser than Earth basalts. Certain carbonaceous chondrites are porous and full of water-bearing clays, so they can be lighter than a typical Earth rock. The famous Orgueil meteorite, which fell in France in 1864, is soft and crumbly.
Weight is also a poor test on its own, because several Earth materials are heavy too. Magnetite and hematite, both iron ores, are dense, and so is slag from metal smelting. Scientists measure density properly by weighing a specimen in air and again suspended in water. As a simple home check, compare your stone with an ordinary rock of similar size, but treat any result as one clue alongside the crust, magnetism and interior.