interesting comparison)) perhaps you can compare bitcoin with gold because gold is an expensive rare and unique resource but the difference is that gold is not so easy to use as bitcoin) you can not pay off a piece of gold as it can be done by bitcoins at any time and almost everywhere!
there is something they have in common, yet they have a lot of differences. There can be many more bitcoin replicates created with the same code, yet there can't be the same gold with the same chem composition.