I choose the larger square, because the smaller square is just too small.

What is the application? Are you using both the carrara tile and the glass tile on the same wall? Not two things that really go together...

None they do not go with the cararra at all

Melissa Gallagher, it's for a bathroom. Thank you all for your input. I really appreciate it. But now I'm stuck.

So this photo (bottom) was my original inspiration for the bathroom--glass, mosaic and carrara tile--and it was on display at a very upscale tile resource, so I trust that it's "a thing." I especially love the pop of aqua with the carrara tile. My contractor works with a different tile vendor, so I was forced to shift gears.

For those who don't like the combo, can you please give me some direction? If I stick with the 6 x 12 carrara porcelain tile for floor and walls, how can I accent to achieve a spa look with tile? Also I'd like to do aqua painted walls. Attached are some BM paint colors I like. Thank you all so much! This is a big, expensive project, and I want it to be right.

So, for you to follow your inspiration photo, you need to pick a mosaic that's a better match than the ones pictured. in the inspiration photo, the mosaic has both stone (Carrara) and color of the glass, look for something similar.

I don't trust my monitor, but here are a few candidates...

Good luck finding just the right thing!