Around 75% of the flavors are gluten free. Nothing is marked explicitly, and the worker had no idea about gluten. He suggested sorbets while they have many flavors that are safe. Then he pulled out a very old allergen list from behind the counter, make sure to ask for this. Every flavor has its own scoop so it looks safe, however some GF and non-GF flavors are next to each other so you might want to avoid them just in case crumbs fell into them.
Called the owner before visiting to ask about how Gluten free options are handled. He seemed very receptive and accommodating. When we showed up on a whim a few days later he had separate serving spoons cleaned and waiting. He scooped from the front with a fresh spoon like they do in Italy and was very careful. Obviously the Gelato was amazing as they are affiliated with the Italian chain of Florence. We will definitely be visiting here frequently.