Okay, now *this* is why a mod would lock a thread... *laugh* >:D

nope, Newcastle, I think

Okay, my Google Fu is strong today. What MTM is referring to is the group of classical greek marble sculptures from the Parthenon displayed in the British Museum. This of course indicating that Marble will last on the order of millenia.

Marble is, of course, metomorphosed limestone: more durable, yet having the same susceptability to dissolution in acid. Acid rains can occur naturally, usually as a result of volcanic activity, and most rain does have some sulfides in it, making it effectively very dilute sulphuric acid. Thus marble will slowly be dissolved over time when exposed to the elements.

Of course, some granites, particularly pegmatites, have large crystals that have natural weaknesses at the intersections between minerals. These contact faces can fairly easily have water action or even plant roots pry them apart. Certain rocks often grouped in with ganites, particularly granodiorite, have much tighter crystal structures, and are thus much less prone to erosion in these ways. In fact, the Rosetta Stone is made of granodiorite.

True diorite is considered the hardest rock (as distinct from minerals) to work, IIRC.

_________________
SG

Ghost's Paint Blog, where everything goes that isn't something else.

Somebody please lock this thread... It is out of control.

Oh I forgot, I can lock it! In fact I did lock it until Chroma reared his ugly Eldar head.

I think we've answered the questions... and then some.

_________________
author of Syncing Forward and other stories...

It's a dog-eat-dog world, and I've got my Milkbone underwear on.

I like beef.

_________________
Currently doing a plastic scenery kickstarter