You are viewing a single comment's thread.

view the rest of the comments →

0
2

[–] oedipusaurus_rex 0 points 2 points (+2|-0) ago 

OP's post was accurate even assuming that your complaint is valid.

Saying a rock is 4 billion years old is the same as saying that it formed 4 billion years ago.

A rock is a rock as long as it doesn't weather into aggregate (some of it will, but the aggregate part becomes sand/dirt), and as long as it doesn't melt. Gneiss is incredibly hard. It's basically tempered granite/schist.