Looks real nice...almost as if I'd done it 
You may have found this out already, but with joints that size you would be better off using a grout brand that has a little larger sand to it. For instance, the brand Home Depot carries has a lot finer sand in it and is what I use for smaller joints or when I need sanded grout but want to minimize scratching of the stone surface. This brand will wash out of the joints real bad during the grouting process. For larger joints where I want the grout to stay as full as possible I use C-Cure brand as it's aggregrate is considerably larger and thus the joints stay fuller. It's also easier to clean off the face of the quartzite (good call on the pre-seal).
I'm not going to list the local distributors of C-Cure, but if you need them just PM me.
Also, be REAL careful with the freezing weather we've got coming up. It will do BAD things to fresh cement based products like grout.
You may have found this out already, but with joints that size you would be better off using a grout brand that has a little larger sand to it. For instance, the brand Home Depot carries has a lot finer sand in it and is what I use for smaller joints or when I need sanded grout but want to minimize scratching of the stone surface. This brand will wash out of the joints real bad during the grouting process. For larger joints where I want the grout to stay as full as possible I use C-Cure brand as it's aggregrate is considerably larger and thus the joints stay fuller. It's also easier to clean off the face of the quartzite (good call on the pre-seal).
I'm not going to list the local distributors of C-Cure, but if you need them just PM me.
Also, be REAL careful with the freezing weather we've got coming up. It will do BAD things to fresh cement based products like grout.
