ANSWER: You must use an ASTM C920 silicone sealant suitable for granite. Laticrete has a product called Latasil that comes in many colors. Dow Corning has a product called 795 or 790 that comes in a variety of colors and they say it's suitable for most stones. Once again, silicone is the best putty for kitchen sink splashes with a quartz structure.
Experts recommend Loctite 100% silicone for this task. Silicone is once again saving the day, as the best putty for kitchen splashes with a quartz structure. Experts recommend Loctite splash silicone, 100% made from 100%, for the use of splash protectors. Silicone is the best choice when you are going to seal something related to water: bathrooms, kitchen utensils, bathtubs and even fish tanks.
Acrylic is a good general purpose sealing substance, perfect for small gaps between baseboards and chair railings.