Don't forget that there are zircon grains around today that are nearly as old as the Earth. There are zircon grains dated at over 4.4 billion years old. They'v

Don't forget that there are zircon grains around today that are nearly as old as the Earth. There are zircon grains dated at over 4.4 billion years old. They've survived _a lot_. These are zircon grains that have survived everything else around them being melted and metamorphosed multiple times, then eroded, then redeposited, etc. We don't really know anything about the rock they originally crystallized as a part of, but the individual zircons are almost indestructible and make it into new rocks as old rocks are destroyed. They're also massively useful as a "fingerprint" of what rocks eroded to produce a particular sediment. You can identify things like river drainages switching through time by what zircons are in sands. (Search for detrital zircon geochronnology.) It's incredible what you can piece together by looking at zircon grains!