Chondrites, the most abundant type of stony meteorite, are very primitive in terms of chemistry. They also contain many of the first objects to have formed in the solar system, such as calcium-aluminum-rich inclusions and chondrules (from whence they get their name). Most chondrites also contain tiny flecks of nickel-iron metal.
Chondrites represent the oldest solid material within our (The sun with the celestial bodies that revolve around it in its gravitational field) solar system and are believed to be the building blocks of the (Any of the celestial bodies (other than comets or satellites) that revolve around the sun in the solar system) planetary system. Hence, from the abundance of chondrules within these meteorites, it follows that an understanding of the formation of chondrules is important to understand the initial development of the planetary system.
A 7.92 gram slice of NWA2889 an L/LL 3-6 showing multi colored chondrules of all sizes.
Chondrules are formed by a rapid heating within minutes or less of solid precursor material to temperatures between 1500°C and 1900°C and subsequent melting, followed by a cooling within a few hours. However, the environmental setting, the energy source for the heating, and the precursor material are not known. The solar nebula or a protoplanetary environment are possible places of formation.
In contrast, the fine grained matrix, in which the condrules are embedded after their accretion into the chondrites parent body, is assumed to have been condensed directly from the solar nebula.
A 6.2 gram slice of NWA1933 an LL3 again showing multi colored chondrules and one of my personal favorites.
The above chondrites as you can see have no visible metal and thus are not good candidates to hunt with a metal detector in most cases. There are many chondrites in both the L and H class that do have enough metal for a detectorist to hear though and will actually give a very good signal. Below are a few samples that are easily heard with a VLF or PI detector.
Trilby Wash, an L4 has visible metal and some interesting chondrules. This meteorite gave a good signal on my detector.
Some chondrites have large amounts of metal showing in their interior such as the Franconia pictured below and you guessed it, they really sound off on a metal detector
Franconia H5 Chondrite showing allot of metal and some chondrules as well.
Less common, comprising only a few percent of all meteorites, are achondrites. These are also stony meteorites composed primarily of silicates, but these meteorites have experienced familiar geologic processes of melting and differentiation - although these happened long ago. Most achondrites formed on asteroids during the birth of the Solar System, but a small number formed on Mars and the Moon.
There is much more to be said about chondrites, but there are fascinating out there with much more detailed info from those much more qualified to explain. My focus will remain on the identification, hunting, and collecting of these fascinating visitors from space.