Verified answer

depends what the composition of the meteorite is, for example, if it was full of Nickel it would take longer to break down than if it was full of Iron. Also depends on the size and density of it. Just a roundabout guess though, I would say it would be indistinguishable from its surroundings, except maybe when under close study and observation, in about 1 - 100,000 million years time.

I would have to say educatedly, it would depend entirely on what type of meteorite it was.

Let's put it this way. Regardless of what it was made of, to survive the Earths atmosphere and actually land, it would be around a few million years.