Really, I don't know. They're homogenous from what I understand, being made up of mostly the same material per asteroid, but how are they formed? :confused:

From what I've heard, they are chunks of an old planet or moon from when the Solar System formed (it was pretty violent back then you know)

One possible explaination...
Asteroids orbit between the orbits of Mars and Jupiter. Scientists think that there are two ways that asteroids could have been formed. One of their theories is that they were all once thousands of planets and they ran into each other and turned into tiny pieces of rock. Their other theory is that they are all from a mother planet that was broken off into tiny chunks.
They think that the thousands of planets were in between the orbits of Mars and Jupiter. That is were all of the asteroids are. One day a big shake of the Milky Way Galaxy spun the planets out of orbit then they crashed and crumbled into the tiny asteroids.
The second way they think that it happened was that there was a mother planet in between the orbits of Mars and Jupiter and the planet wasn't completely solid. Huge chunks came off of it and floated away into the orbits between Mars and Jupiter.
source (http://www.carlinville.macoupin.k12.il.us/middle/cms2002/space/astr.htm)

Another possible explaination:

The vast majority of all interplanetary material that reaches the Earth's surface originates as the collision fragments of asteroids that have run into one another some eons ago.
source (http://ssd.jpl.nasa.gov/why_asteroids.html)

Yet another:
Most main-belt asteroids (including 1 Ceres) have spectra similar to carbonaceous chondrites. This suggests that they are mostly undifferentiated bodies that have had very little heating in their histories. In the inner part of the main belt we see more asteroids that look like ordinary chondrites. Since asteroids in this part of the belt can travel most easily to the Earth, most meteorites are from this group. A handful of asteroids look like iron meteorites. To concentrate the iron, a body has to become differentiated. Then it has to be shattered in a collision to bring the iron core to the surface. The “mantle” would become the achondritic meteorites. This is about a close as we get to the hypothetical "missing planet." One of the largest asteroids, 4 Vesta, has the spectrum of an iron meteorite. This could be the ancient core of a differentiated asteroid

What I ran into was varing theories on how it could. None of these sites are definitive sites. Do you have a thought on how it could?

So was I right? To some degree?