Can't wait to read the article when I have more free time. I just have to say, I am so impressed with your work here. You are making a big difference that will benefit consumers everywhere. Hopefully you are being compensated for your expertise and effort.

Dream, I'm not sure about sealers for Taj Mahal, but I do know it's one of the more robust quartzites out there. Our local fabricator showed me a stack of broken cutter heads from fabricating that stone.

Phew, indeed CPA! That's also the result we'd expect from that stone, so I'm glad it's behaving as it should.

Rjknsf, thank you. This started out as a labor of love for geology and a concern for customers. I do get paid for the work I'm doing now, which allows me to be more thorough and helps spread the message farther. I've really enjoyed the writing and the teaching too, so it's a win-win!

Glad to hear it Karin, I really appreciate all the effort you put into the forum here. It's people like you that help this community thrive.

Karin, thanks very much. Our stone was sold as Quartzite but because I had read here and did my own tests we bought it knowing it was marble. I did tell the stone yard that it was marble and they said it was a 'soft quartzite.' I do see quartz in it and we haven't had issues yet but we are babying it. It was called Arni Bianco.

Have you ever run across that before? It sparkles in the light.

Beautiful Pennie! I haven't seen that one but you did everything right by reading up and testing it. Nice job!

Karin:

Great article. I particularly like how you differentiate between 'quartzite" and "quartz" (engineered stone) in the 6th paragraph.

karin_mt, I can't thank you enough for this and the many other threads on countertop geology! We are building a home in SoCal, and I went out on my first slab search this weekend, armed with the knowledge I learned from you. I went to MSI who did not have the Princess White quartzite I was looking for. I did see White Macaubus and Taj Mahal, but neither were "it". I also saw Super White there labeled as a marble.

We went to a second place nearby who did have some glorious looking Princess White slabs that the sale person referred to as quartzite. I was lucky enough to get the last sample they had of it- from a piece that had "broken off a slab when it came off the truck". I was in love. It is gorgeous. I took it home and tested it.

It failed miserably. :(

It etched with white vinegar. It would not cut a glass tile, but the corner of the glass tile scratched the sample. A kitchen knife scratched it's surface.

I'll post pics of my sample and I have pics of the slab if needed. Is this actually Princess White? It didn't look anything like the Super White slabs at the previous place, so I don't think this was a case of mislabeling the notorious Super White; This was bright white with some sparkly depth to it. I know I've read people's positive reviews here on their PW countertops being a real quartzite.

I'm wondering if PW is just not a true quartzite ever, or should I hold out hope of finding a similar look in a real PW quartzite? Was this not really PW? I'm assuming this was maybe a dolomitic marble or something else lower on the Moh's scale... but certainly not quartzite.

Here is the sample. You can see the scratches from the knife and glass tile at the top and bottom ends.

Here is the etch in the center from about 10 min of white vinegar.

I'm still confused about quartzite. After reading every post here that I could find on the different stones, I fell in love with Fantasy Brown Quartzite. We have one local shop here that has their own stoneyard and they've been here for as long as I can remember. Other than that we have 2 lumberyards and Home Depot and Menards. At each of these places when I asked to see their quartzite, they had no clue what I was talking about. Some of the sales people asked if I meant quartz. And no one had heard of Fantasy Brown either. Has anyone else ran into this? I think I will probably end up getting one of the High Def Laminates, there was quite a big difference between it and stone.

WOW! Such a useful article, thanks SO much!

Science for the win!

22k22, you did a masterful job with your tests - well done! And you saved yourself from certain heartbreak.

I don't know the answer to your question about the naming. Because the labeling is so unreliable, I think you could hold out hope for other slabs being actual quartzite. After you see and test a few different batches of Princess White you'll probably get a sense if it's all the same or not. Keep trying!

Cindy, the salespeople are often not as up to speed as we might like. If a shop doesn't know the difference between quartz and quartzite, that's not a very promising sign of their knowledge. Reputable stone dealers ought to know the difference. Fantasy Brown is not pure quartzite though. Some of the layers are marble. That's one of the trickier ones to figure out. Good luck with your search!

Great article, thanks so much!! I'm still not sure about the one I have my heart set on (Dolce Vita quartzite). Didn't etch but didn't scratch glass either. In the end it probably doesn't matter because I'm going to get it anyway:)

track that is gorgeous.

Thanks, cpartist. Means a lot coming from you - I have loved yours from the first time you posted! It's truly beautiful and I can't wait to see your finished kitchen.

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Hi Karin,

i was reading that all quartzite have resin pumped in them because it is a brittle stone. Therefore it makes some quartzite etch because of the resin that is used.

Resinating a stone does not cause it to etch.

Joseph, it's the resin that etches. I have to find the section from Marble Institute of America. Some resin etches.

Beachem, if you have it, please send me some documentation about this. Or better yet, a stone sample. I am working directly with the Marble Institute of America about quartzite and this topic has not come up.

Also, it is certainly not true that all quartzite is pumped with resin. It's not necessarily any more brittle than other stones. IMO, any stone with that much resin in it would be a poor choice, regardless.

When I was researching quartzite (all the reading's one huge blur now!), I did recall coming across these two, here and here (the latter, see 6/7/2011 post). They both reference MIA (one being a phone call by the fabricator, so who knows what may have been either miscommunicated or misinterpreted), but I wasn't able to find anything on the MIA website itself.

ETA: Somewhere along the way, I did read/hear that due to the brittle nature of Macaubus White (and crosscut version Calacatta Gold), this stone is indeed resinated to prevent from breakage during transport (from Brazil to the US) -- however, no discussion of resin and etching.

Does anyone know whether you can roll dough on quartzite? None of the slab yards I went to gave out samples so now I'm committed to the Taj Mahal. But I'm wondering about the rolling dough on the counter.

Karin, it's been awhile. I just tried to search on MIA site and everything comes up with error 404.

Interesting that this site stonesource.com cited quartzite as lots of fissure.

I was reading the fabricators forums last year and they do complain about resin usage and quality of quartzite depending on where it was sources.

Here's a picture of the backside of a slab of Madreperola. The dark area is where the resin is 1/8" thick.

Karin, thank you for this wonderfully informative article. I too, had been baffled by the terms such as 'composite stone' because my high school geology had always referred to it as a metamorphic rock not a 'man-made composite'. So glad to hear this so that I'm well informed when I decide to remodel my kitchen. Thank you again!

Thanks Goldblush!

Beachem, I emailed the MIA today and asked about the resin question. They said that this claim is not true. Resin does not etch from acids, particularly normal kitchen/cooking acids. Resin is affected by solvents, not acids.

The link that Javiwa posted to "Candy's Dirt" blog is one they are particularly unhappy with because it pins a false claim on them.

As I said above, any stone that is relying on resin to hold it together is one I'd be wary of. But this is not what's behind the etching problem. In fact, the etching problem is quite simple, because it's a case of mistaken identity of the stone. Very easy to diagnose and solve.

Thank you karin_mt.

Thanks Joseph - my current assignment for MIA + BSI is to write a technical document about quartzite for dealers and sales staff. We'll keep chipping away at this topic! (No pun intended.) Hopefully we'll keep making progress in improving people's understanding. Thanks for your support!

karin_mt - I hope you don't mind me asking you more geology questions! I'm under a bit of a time crunch to make a decision and really trust your expertise in geology. :)

I was going to go with this White Princess below in pics, and was assured it was not a dolomite. However, I've read that the glass-like translucent crystals throughout cannot be true quartzite, that those areas are characteristic of calcite. Quartzite wouldn't look like translucent glass.

I was also assured that when laid flat, the snot-green deposits would look clear/gray and not green all over the counters. Can that be true? Here are some pics of the WP and then below I'll add a photo of a Sea Pearl that is our other option. Not as "spectacular" as the sparkly depth of the WP (unless it looks all snot-green installed!) but the SP is half the price.

I really had my heart set on the WP but am worrying about it containing a lot of calcite. I asked for a sample and the only one available was from another WP slab that was mostly the white part and didn't have the translucent crystal-ish parts. Vinegar didn't etch it, and it scratched glass with some effort- but again, my slabs have a ton of the translucent parts.

Thanks for any advice or comments! :)

close up on translucent parts:

the green that is also throughout:

and then the SP: (spic taken indoors so may be slightly dark)

22k22: Would the stone yard consider sending you home with a sample that included the green portions, so you can see for yourself if the greens will indeed appear gray?

I am constantly amazed at the things people will say to sell stone and the lengths people will go to believe them when they're in love. Women are safer in a singles bar. At least there, their guard is up and their mistake isn't going to cost them any money. That regret will pass at sunrise; this one will remind for a decade every morning.

BTW 22k22, I love that green color in the slab. Hope it's a true quartzite for you.

Joseph Corlett, LLC, I'm not sure if I'm supposed to take that as helpful or a complete insult on behalf of women everywhere. ;)

Fell in love the this AuroraBlue Quartzite so out of my comfort-zone but I love it! - I was so anxious that I'd have to start all over again. and after reading all the post I got a piece from the supply - Yeah it etched the glass bottle - then onto the staining - ketchup, red wine, balsamic vinegar, lemon juice and a sharpie . We left in on overnight - everything was clear except the sharpie which left a shaded spot. I'm not overly concerned about the sharpie so we'e going to order . When I brought my DH to see he granite he also said it looks like a piece of art - I'm so excited. Thank you karin_mt for educated all of us.

22k22, the large translucent areas could indeed be quartz, it could be calcite, or it could be epoxy filler. There's no rule of thumb, aside from testing those areas.

I was looking at a "gemstone" slab at a showroom that had large translucent crystals. "This is gonna be calcite," I said as I did the tests. Wrong. It was quartz. The staff was relieved and I was embarrassed!

Just a shout-out that I don't check these threads too often and I most likely can't respond to individual "is this real quartzite" type questions. I'd love to have the time to help every person individually, but that would be a part time job in itself. So that's why I wrote the guidelines. Just about every question imaginable has come up on the various Countertop Geology threads, so that's a great place to look.

That said, I'm still around and I will check in now and then. I really enjoy this community!

Thank you karin_mt I appreciate your feedback and totally understand. As I doubt I'd be able to really test those areas I'm a bit weary indeed.

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this is the BEST article out there about Quartzite. I literally just put my order in for Cristallo Quartzite. Do you have any advice/info about this stone?? I have shared your article with my husband and fabricator! Bravo!

Hi karin_mt

Do true quartzites stain? I have been reading that some are more porous than others. If this is true, are the whiter ones more porous? Thanks so much for all the info you have provided!

Yes, quartzites can stain. The whiter ones are not more porous, necessarily. White Macaubus is one that is more porous, so for sure that one needs careful sealing. Aside from that, I have not heard of others that are troublesome. Taj Mahal and Sea Pearl and Fusion are all dense ones. But staining is something you can test for, and resolve with sealing.

Sorry, I didn't notice the comment from Karen G. above. Hopefully it worked out well!

I know all of this from years on these forums, yet still bought the Taj Mahal slabs for my kitchen without doing any tests! There were 10 slabs and they were exactly the look I wanted and were on hold for someone else. Told the stone yard I wanted 3 of the slabs now! They made some calls to the people holding them and I owned them the next day. No samples available to test. Still planning the kitchen, but my counter material is a done deal! I've never babied a stone counter or worried too much about patina from everyday life, so I don't anticipate any issues.

Thank you Karin for your response! Have you heard of veyron quartzite? Do you know if that one is porous? We are currently trying to decided between that one and calcatta. From what I've read, calcatta is basically the same as white macubus. Kind of nervous about that one because it will be porous.

breezerj: Calacatta is the crosscut version of Macaubus, so they're the same stone. We installed Calacatta (honed) and sealed it with Tenax Proseal, which makes the stone resistant to both water- and oil-based liquids.

Haven't heard of Veyron, and Javiwa is right about Calacatta. Tough decision! But you can't go wrong, IMO.

We picked our slabs today! We decided to go with the calcatta, this is one of them. It's hard to do the glass scratch test because most slabs are wrapped. We did find a spot on the other slab that was exposed and it did scratch the glass. Also brought lemon juice with me. Didn't etch! I'm very pleased with our decision, just hoping they will be sealed correctly. Thank you so much Karin for all the info you have posted! Definitely made it easy to know exactly what we were looking for!

I am nervous and possibly heartbroken. I have spend weeks looking for a countertop and yesterday I found the perfect slab (I think). It was honed quartzite Cardoso, exactly what I was looking for. It is hard a nails, it took a good 5 mins wacking at the slab to get a sample. I got home and without much effort, it etched a glass. Here is my concern, I put some lemon juice on it and it darkened the honed top, although the untreated edges were fine afterwards. So this morning I put some borscht I happened to have (beets and citric acid), and once again it is slightly darkened. It is not sealed, should I find another countertop? I am not super careful, and although I am fine with sealing it annually, I don't want to worry if someone puts something on it overnight

Tough call. We have to overlook shortcomings in our loved ones, human and countertops, but you aren't married yet.

It is not sealed...Take a clean sample of the stone to your fabricator and ask if sealing the tops are included in his pricing. If so, ask him if he'll seal the sample and let you bring home to test.

Tamarcita, I had the same concern before we purchased our calcatta quartzite. My advice would be to seal your sample and then do stain test for an hour, 3hrs, overnight, etc. Our stone is known to be porous but with the sealer on, it didn't absorb anything we tested except red wine left overnight. Even that stain has faded. We tested our sample with Miracle 511 porous plus.

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Karin G, hello. I am thinking of choosing the Cristallo. Did you choose the Cristallo? How are you enjoying it? Can you please post a close-up of your countertops?

Thank you