Meteorites can be subdivided into three groupings on the basis of how much silicate material compared to iron they contain: (1) Stones; (2) Stony-Irons and (3) Irons. Stones are by far the most abundant meteorite type and are further subdivided into chondrites and achondrites, essentially on the basis of whether or not they contain mm-sized spherical objects known as chondrules.
The Chelyabinsk meteorite is an example of a “Stone” in that it contains a significant amount of silicate material and only a small percentage of Fe, Ni metal. Image: Wikipedia
The photo above shows a thin slice of the Fukang pallasite an example of a “Stony-Iron” meteorite. The transclucent crystals are olivine, a silicate mineral which is surrounded by opaque Fe, Ni metal. Stoney-Irons are roughly a 50:50 mixture of silicate and metal. Image: Wikipedia
The Hoba iron meteorite is an example of an “Iron” being composed predominately of Fe, Ni metal. Image: Wikipedia
The circular features in this image are known as chondrules and are thought to have formed as molten droplets in space early in solar system history. Meteorites that contain chondrules are known as chondrites. The diameter of the largest chondrule in this image is about 0.3 mm.
ALH 81005 is a lunar meteorite that was discovered in Antarctica. It doesn’t contain chondrules and hence is an example of an achondrite.