what is pompeii granite made of?

Dear Barbara:

I have no idea what the real nature of Pompeii “granite” is. I know for sure that it is not true granite, but other than that, it's virtually impossible to guess the mineralogy of a stone by just looking at it. If you want, marblecleaning.org has available a mineralogy test for the modest amount of $500.00. All you have to do is to send us a little piece of that stone and within a couple of weeks we'll have the whole story for you, in all details. (And BTW, marblecleaning.org is nonprofit, and not one red cent of that fee will ever see its way into my pocket…)

Now, you may be wondering how come I'm so sure that's not true granite, if I don't know what it is.

Well, just take a look at that stone: with all those large insertion of chunks of different rocks, and all the movements in its texture, does it look like the solidification of a molten mass to you?... The first prerequisite for a stone to be classified as granite is that it must be an igneous rock. And an igneous rock is exactly the result of the solidification of a molten mass of different minerals. There's no way that an igneous rock could contain such large chuck of unbroken rock and could show “movement”. That must be a metamorphic rock that started from sedimentation first. Some of the components may even be igneous, but that does not make it an igneous rock by any stretch of imagination.

That said, there's no way to tell how absorbent it is. It may be absorbent in its natural state, but just about all those so-called “exotic granites” are resined by the factory (many of them could not even be held together without the resining process). The resining alters greatly the original absorbency rate of the stone and, in certain cases, it even almost totally eliminates it.

However, I hope you will understand the true meaning of what I'm about to say. It appears to me that like most other inquirers at this stage you seem mostly interested in the type of stone and/or its physical characteristics. It's human nature at work, I reckon! :-)

How about if I tell you that a certain stone is a good choice and then you get a low-grade slab? Trust me: the human factor is far more important than the stone itself and should be the only true deciding factor!

In an industry that's virtually unregulated, how good and reputable the fabricator who's is going to process the stone you'll end up choosing is far more important than the stone itself. None of the horror stories that get posted in this very site stem from the stone itself: they all stem from the fabricator. That is why I seldom make final statements about any one particular stone. There may be differences within the same stone (and I'm not talking about looks, here!) from one bundle of slabs and the next. The slabs may have also been either “doctored” (which is bad), or “resined” (which overall is good) by the factory, which would make a big difference. Even more important, what's a good stone in the hands of some “Michelangelo”?! And again: a reputable fabricator will only carry high-grade slabs, not some “special!”

We have available a very comprehensive article on “How to Shop for a Granite Kitchen Countertop” that will give you all the intelligence you need to venture yourself with confidence in the stone industry jungle, and it includes the world renowned “Lemon juice (and oil) test”! It does carry a small price tag, and you can order it by logging on the Educational Literature section at: http://www.marblecleaning.org/literature.htm. It's available in pay-per-download format and I consider it a cheap “insurance premium” to pay when there are thousands of $ involved! Not to mention the little and much needed support you'd be giving to the cause, your cause, since every single penny of the cost of the article will be used to support it.

Also, will you please read and e-sign our Statement of Purpose at: http://www.marblecleaning.org/purpose.htm? By spreading the word about this valuable site among your friends & family and the stone trades' people you've been dealing with you will be rendering everybody a valuable service!    

Also, do take advantage of the plethora of FREE Helpful Hints available at: http://www.marblecleaning.org/helpful-hints.htm. They're on the house!

Thank you.

Ciao and good luck,

Mauri z io Bertoli