Fossils are stone. The porous bone that housed the minerals are long gone by the time we find them.

We are talking about actual bones in living animals though, and those surely fossilize (preserve over eons) much more rarely than many civilizational artifacts.

> those surely fossilize (preserve over eons) much more rarely than many civilizational artifacts

They wouldn’t fossilise. That’s specific to the porosity of organic tissue. They might be preserved, but the Cambridge paper explains why it’s unlikely they would last for a hundred millennia or more.

But surely it is much more unlikely that animal bones would last for a hundred millennia.

> surely it is much more unlikely that animal bones would last for a hundred millennia

Why? The Cambridge paper gives a scientist’s reasons for that not being the case being supposition.

Because processed stones are much more massive than bones, which mostly rot away quite quickly.

Mass does not matter. Tungsten metal is heftier that the stone and it rots regardless.

Let's say durable then.