Stony meteorites are the most common type of meteorite, accounting for about 94% of all known meteorite falls. They are primarily made up of silicate minerals, similar to the rocks found on Earth. These meteorites provide a unique glimpse into the early solar system, as they are some of the oldest materials available for study.

Stony meteorites are divided into two main categories: chondrites and achondrites. 

Chondrites are the more abundant of the two and contain small, round particles called 'chondrules', which formed from molten droplets of dust and rock in the early solar nebula. These chondrules are among the oldest solid materials in the solar system, dating back over 4.5 billion years. Chondrites are often considered 'primitive' because they have not undergone significant alteration by heat or pressure, making them valuable for studying the original building blocks of the solar system. They also contain small amounts of metal and organic compounds, which can provide insights into the origin of water and life on Earth.

Achondrites, by contrast, do not have chondrules and have been significantly altered by processes like melting and differentiation. This means they come from larger bodies, such as asteroids or planets, where heating caused the materials to separate into layers. Some achondrites originate from the Moon, Mars, and known asteroids like Vesta, making them particularly rare and scientifically important.

Stony meteorites, with their diverse compositions and histories, offer valuable clues about the formation and evolution of planets and asteroids, helping scientists piece together the history of our solar system.