Your kitchen sounds beautiful! Love soapstone. My marble was sealed after installation, but prior to grout. Grout color is tricky - at least for me. Do a sample board and select grout in different colors. I am unable to look at the little grout samples and say "that's the one." Best of luck

Actually, there ARE sealers called grout release agents. Also water based sealers actually act better as grout release sealers. But for something like quartzite, the 511 will do just fine, and the stone will stay sealed alot longer than it will with a water based sealer. This was where my quartzite learning curve began:

Many glass manufacturers do not allow the use of epoxy grout with their product. You must contact the manufacturer for this information. If there are no instructions in the box also inquire as to which setting material is called for. Some glass may require mastic instead of mortar. While you have them on the line ask about thermal shock rating. You have a large format glass tile (9 square inches is large format for glass) If you have a cook top, especially gas simply boiling a pot of water on the back burner could crack the glass tiles due to thermal expansion. Just a few things the DIY shows and box stores won't mention. Was any of this mentioned to you at your point of purchase? Always test grout first to verify it will not scratch the glass. Other grout manufacturers such as Ardex, Bostik, Tec should be considered also. Some make grout specifically for glass. I do not recommend glass tile installation for a DIY'er. or a GC/ remodeler. There is a lot more to it that I did not mention. Proper cutting, setting, polishing etc. If you think hiring a professional is expensive wait until you see the cost of hiring a amateur. Good luck with your project.

Once you touch it you own it. 4x16 is a large tile for a backsplash. If you have a cooktop be aware simply boiling a pot of water on the back burner can crack the glass due to thermal shock but I'm sure whomever sold you the glass warned you:)