I just built a quartzite patio in Reno, NV. I used the new product, polymeric sand and it worked great! I got the sand in 60 lb bags for $20 a bag from Home Depot. My patio is 9X27.5 and I used 5 bags. It looks like regular sand and sweeps into the joints. You then mist it 3-4 times waiting about 10 minutes between each misting. The water activates a weak polymer glue and locks the sand granules in place. We don't have much problems with frost heaves here, but if a stone moves you can pull up the sand in chunks and step on it or use a shovel to get it back to a granular stage, sweep it back in place and re-mist. Although the polymeric sand sets up pretty hard I don't think it would stand up to a leg from a patio chair, etc., so we plan on getting sled style chairs for the patio. It does do well with walking on it and the sand stays put! So far we are very happy with it. I'll let you know how it goes thru the winter. We get very little rain here but we do get snow.

I agree with Bill V--I noticed that even the action of pouring vinegar on the black marble tiles caused a blotchy look. When I 'honed' multiple tiles, I put them in a vinegar bath, so that all surfaces were exposed at the same time. After a set amount of time (5 minutes, I think), I rinsed the tile with clear water, then dipped it in a baking soda bath to neutralize the acid, and followed by rinsing again in clear water. Then wet-sanded and polished the tile to a finish that I liked. I used these tiles on a small counter, 22"x50", and used the scraps on a backsplash mosaic. Doing a kitchen with lots of counter space would be very time consuming. The carrara slab was an already-etched, second-hand find. Because of that, and the difficulty of getting an even etch without a 'vinegar bath', I used only the sanding method on it. The slab was too big for me to take outside, and even with a filter canister on the sander, it produced a lot of fine dust. When experimenting with etching, I laid a vinegar-soaked paper towel on one of the 12x12 tiles. It etched a really neat 'snakeskin' pattern into the tile. I've seen other GW members, experimenting with etching marble, mention the 'paper towel effect,' too. After I polished the tile, it was really neat--almost like a fossil. I loved it, but my husband preferred the smooth finish, AND I was afraid that if I had to sand out any new etches, the pattern would no longer look uniform. So I continue to use that tile as a sample beside my stove. LOL, Bill, haven't noticed any salad smell, but sanding produces a sulfur(?) smell. Also, I dropped some marble chips into a jar of vinegar, and grew some beautiful calcium crystals. If your kid is looking for a science-fair experiment, that's an easy one!

First off, the granite and tile do NOT HAVE to match. They can be as like as twins, or different as night and day to give contrast. It's entirely up to you. My guess would be if it's the same stone as your vanity top, it's going to be a nice accent to your tile. Now, as for your question, best way to know if you need to seal the stone or not is to take a sopping wet sponge and place it on the stone. Give it about 30 seconds or so, and remove the sponge and dry up any water still on the surface. If after that, you can see a darkening of the stone where the sponge was, then you need to seal it. Otherwise, you can leave it alone. If you DO need to use a sealant, Stone Tech's Bulletproof is a good choice.

@avaaustin The process of attaching fiberglass mesh to ceramic/porcelain tile differs from natural stone processing. Mesh on the back of ceramic mosaic usually doesn't have a layer of glue between the mesh "cells". At same time, the main reason of "resin backing" attached to natural stone is to reinforce it and fiberglass mesh is attached using a "glue" that is mostly polyester. It, first, adds an impervious layer to the back of stone and can significantly reduce the evaporation. Secondly, there could be problems with how well the bond is between the mesh and the substrate since dry set or polymer-modified mortars don't adhere to it very well. True porcelain tiles, whether sealed or unsealed, have >0.5% water absorption. At same time, marble is a translucent stone that will still absorb moisture as vapor even after an impregnating sealer is applied. I can't tell you whether Bulletproof sealer will help you in your situation. With properly installed water-in, water-out system and stone with no "resin backing" it is best to avoid any sealer. That's my strong opinion. Sealing the stone but not sealing the grout will not make any difference. Impregnating sealers are all considered permeable but if there is trapped moisture under the stone unsealed grout won't help.