Can a meteorite be round like a ball?
Large meteorites are almost never true spheres; they are usually irregular blocks with rounded edges, or cone shapes. Round balls are usually concretions, slag or ironstone, though microscopic space dust can form perfect spheres.
Pictures of asteroids and science-fiction films may suggest that space rocks are round, but meteorites rarely are. Most are fragments broken from larger bodies, either by collisions in space or by break-up in Earth's atmosphere. They start out angular and irregular. During the fall, their surfaces melt and stream away, which softens edges and corners, but there is not enough time to sculpt a ball. The result is typically an irregular stone with rounded edges, a little like a well-worn pebble.
Some meteorites take on a striking shape called oriented. If a stone keeps the same face pointing forward as it flies, the front is ablated into a smooth cone or shield, while the back stays flatter. These shapes are prized by collectors, but they are cones and domes rather than spheres.
Real round balls found on the ground are usually Earth-made. Concretions are mineral lumps that grow outward inside sedimentary rocks, often around a shell or grain, and many are almost perfectly spherical, sometimes rusty and heavy. Ironstone nodules, cannonball-like lumps of iron sulfide, slag droplets and even old artillery shot or ball bearings also turn up.
The exception lies at a tiny scale. Micrometeorites and cosmic spherules, dust grains less than about a millimetre across, often melt completely as they enter the atmosphere and harden into near-perfect spheres. They are far too small to see without a microscope. Glassy tektites, formed from Earth rock melted by large impacts, can also be round, but they are not meteorites. If you have found a heavy round ball, enjoy it, but expect a terrestrial explanation, and check with a museum or university geology department rather than breaking it open.