pickles; just pickle juice (because if you sil comes by and slams the jar down and causes splashing that you don't see, you will see it later in the day); tomato sauce; lemons; glass with something in it so you can test for rings too.

If you can get more than one piece, run the test on all the pieces but wipe off at diferent times on each one, with one being left on there overnight. Because guess what? Other people will use your kitchen when you aren't looking and you don't know what they are doing, or maybe I should say aren't doing (cleaning up like you would).

Oh, and use a marker on tape to grid off the piece and write what was where during the test.

bee

Dont forget something oily, like you would get if you left unclean bottle of olive oil on counter or someone splashed salad dressing or marinade
Also, I did test for staining because my yard gave me a piece of stone finished exactly as I was going to get it, they brushed it and sealed it while I waited once I was pretty sure on which stone I wanted.
I tested overnight, because if that worked I know I was golden. It did.

I have a cut piece of stone I was told was Quartzite. Passed the stain and etching tests to my satisfaction, but was easily damaged by knives. Is quartzite supposed to be harder than knives?

Quartzite is harder than steel, but it's possible to leave marks on quartzite with a knife. Sometimes those marks are actually the knife blade leaving a trail of metal across the rock, rather than the blade cutting into the surface of the rock.

In other cases a knife can do damage because it's digging into the structure of the rock, without technically scratching it (subtle difference, I know). So let us know more about what you've observed and I may be able to clarify.

A better test of hardness is the glass scratch test, described in the link below.

Here is a link that might be useful: low down on super white

Thanks, Karin. I had read that post and attempted the glass scratch test. The stone didn't seem to "scratch" the glass as much as "scuff" it. I don't know if that makes sense. Both surfaces appeared to be affected. Perhaps they are about the same hardness? Now this was a rough edge and then the cut edge on the stone against a curved bottle glass. I will attempt again if I can find an old mirror or some flat glass that I won't mind damaging. We've already purchased the slab because we loved it so, but I've not seen it mentioned anywhere on GW or Houzz. The stone yard called it Fascination quartzite. I'd be interested in your expert opinion.

Sorry to hijack your thread Heidia!

Here is a link that might be useful: {{!gwi}}

Hi Casaloma,

That sounds likely that both surfaces were affected. One common scenario is that one surface gets scratched and the other one sort of crumbles. One important thing is to inspect both surfaces after you try the scratching. For example, the glass can look like it has been scratched but if you rub your finger along it, it's just a trail of powdered rock and the glass is still in good shape. So rub your fingers across there to see if the glass is truly scratched or scuffed.

I agree it's awkward with a curved glass bottle. I also think that a broken edge will give you a sharper edge than a cut edge when it comes to scratching.

The other possibility is that even if the minerals in the stone are hard enough to scratch glass, the rock itself make break apart as you are scratching. This has to do with how well stuck together the rock is. It sounds like this may also be a factor here.

That's a cool-looking slab and I don't think it's one I've seen before, very nice!

Oh, the glass is definitely scuffed enough to feel it. I was just expecting more of a defined groove, like a cat's claws would leave on your wood table! This looks more cloudy, like we had the glass etched or sandblasted. Not deep, but detectable.

The difficulty is probably in finding a sharp edge on the sample I have. The back side is covered in mesh and the top is polished. I have the end piece that is wrapped in fiberglass of some sort. The other edge is the flat sawed off side and the two short ends are jagged breaks. No matter. As I said, we fell in love with it and already purchased it. We'll just be sure to always use a cutting board on it!

Just curious Karin, can you tell us anything about the stone from just looking at it? We found it at a yard about 3 hours from home. No one here had ever seen it and I can't find much information on it.