It's an Iron meteorite that originated from the asteroid belt between Mars and Jupiter, and could have been knocked out of it's orbit by colliding with another asteroid. The only difference between asteroids and a meteor, is that a meteor has passed into the Earth's orbit and is either burned up in the atmosphere or falls to the Earth then it becomes a meteorite. They are generally made of iron, silicates and rock.
Excuse the crappy model shot but I wanted to show you guys what it looked like on! It's quite a heavy and substatial piece and I do keep meaning to get a slightly sorter chain for it, but I just love how it looks on. It's really simple and subtle, but obviously the sentimental value for this is pretty massive! Plus it's not every day I get to wear a thing that was in space for a few billion years. The shop this is from is called Jurassic Jewellery, and they have some really lovely pieces!
What do you think of jewellery like this? Is it something you would try?