Marble, quartzite and other rocks in the kitchen
The thread about Super White, quartzite, marble and all things stone has run its course up to the 150 post limit. Who knew we'd all have so much fun with that topic? So we'll start a new one here. I guess the first thread was Rocks 101, so this one must be Rocks 102.
I'll reiterate some key points here:
Quartzite and marble are hopelessly (deliberately?) mixed up in the decorative stone industry. My point, aside from just loving rocks, is to help folks learn how to tell the difference between the two so you are not at the mercy of a sales rep when a multi-thousand dollar purchase hangs in the balance.
Quartzite is much harder than marble and will not etch when exposed to acids. You can tell the difference between quartzite and marble by doing the scratch test.
Take a glass bottle with you when you go stone shopping. Find a rough, sharp edge of the stone. Drag the glass over the edge of the stone. Press pretty hard. Try to scratch the glass with the stone.
Quartzite will bite right into the glass and will leave a big scratch mark.
Any feldspar will do the same. (Granites are made mostly of feldspar)
Calcite and dolomite (that's what marble and limestone are made of) will not scratch. In fact you will be able to feel in your hand that the rock won't bite into the glass. It feels slippery, no matter how hard you press.
PS - don't press so hard that you risk breaking the glass bottle. You shouldn't need to press that hard!
That aside, we can talk about other rocks too. Coal, pumice, sparkly crystals, you name it. OK, I guess we're mostly interested in kitchen rocks. :)
Here is a link that might be useful: the lowdown on Super White (aka Rocks 101)
This post was edited by karin_mt on Wed, Feb 27, 13 at 23:41