IMO, yes, it's too busy and with what I'm seeing on my monitor, it's not the right color either.

Do you have an overall idea of what look you are after? For example, I knew that I wanted my cabs and counter to be the star and therefore wanted a "quieter" backsplash. With your counter, I'd opt for something a little more calm for your BS as well.

p.s. I love your floor choice. And the rest, too, but especially your floors. :)

Agree with ck-squared. Your BA should be the star, and while that BS looks nice with your small sample, I think it would make the whole kitchen look too busy when you are looking at full counters of BA (which I love!!).

On my monitor the colors of your backsplash material look good, and the lack of strong contrast doesn't seem busy. But adding in the variation of tile size might make it so.
Backsplash decisions are really hard, and you have a lot going on with those gorgeous counters, and the strong contrast between the cabinets and floors. Do you have some inspiration photos to look at?

Agree with those who think it's too busy. Also, in my area (DC), glass mosaics are already on their way out.

The BS can go in anytime, so I suggest waiting until your cabs and counters are in before choosing a BS. Then, get your contenders down to a few and make 10-20 color copies of each (yes, lay the tile on the copier!) and then tape them up to get an idea of what a long expanse of the tile would look like.

Another option is to also do your BS in the granite. All the tile I liked was very expensive and I have a small kitchen so we ended up just using the same granite and it wasn't much more than the tile...creates a very cohesive look and I am happy with it....and it really shows off the granite more.

It's too busy. I would look for a cream or tan solid color backsplash. A solid(ish) color would add texture but not complete with your BA. You want your eye to go the the counter, not the backsplash.

If you had chosen a quartz, the this BS would work. I'd go for something simpler. My friend has lots of natural hickory in her house, and it really is a star.
Do u want a tile or a glass?

I have Bianco Romano Granite and looked at glass tile ...similar to what you are showing but in a different color...and felt it was much too busy.
I want my granite to be the focal point....so with suggestions of many on here...I have finally ordered a soft cream beveled 3x6" Subway tile...just today. I think the beveled with give just enough texture and interest without competing with the granite. And like others have said....sometimes the BS is the hardest to decide upon....so just get your kitchen all put together and then take time to adjust to it....Then pick your BS...seems like many on here wait several months into a yr or longer before making a decision. By the way..your cabinets, floor and granite are all lovely!