If you have a spot of super glue, Crazy Glue or Gorilla Glue on your quartz countertop, don’t worry, it can be removed.
These fast drying glues tend to adhere to quartz quickly and firmly, so it’s not likely that soap and water will work, but start there. Use warm water and a soft rubber or plastic edge to gently scrap the spot (e.g. rubber spatula or plastic baking scraper).
If that doesn't do the trick you’ll need three things:
Put some of the acetone/water mixture on the pad or towel and get the glue damp. Try to keep the acetone only in the area of the glue, allow it to sit for a few seconds. (Do not allow acetone to sit on the quartz surface for long periods of time.)
Holding the razor blade almost flat (try for less than 45 degrees to the surface) very gently scrape the glue. Use a light touch, it should start coming off almost right away. Don't press the blade into the counter, just slide it across the surface and let find its way under the glue.
Watch the surface closely as you are scraping, look at it from different angles. Adjust your angle and the lighting will help you ensure you're getting all of the glue and not scratching the countertop.
Repeat the acetone application and scraping until all of the glue is gone. Immediately wipe up any excess acetone when complete.
Lastly, thoroughly clean the countertop. Use a mild soap and warm water mixture, or a quartz-safe cleaner.
While this is an aggressive, and slightly risky tactic (remember, quartz is scratch resistant, not scratch proof), if you’re dealing with hardened glue, it may be your best option. Just take your time and be gentle, and that glue will be gone for good.
Note, you should check with your manufacturer to ensure it is safe to use acetone on your particular brand of quartz, while this is generally fine, the use some chemical products may not be supported by your warranty.