Grow a dazzling crystal that glows in the dark! You won't believe your eyes, it's so easy! Pour the formula into the water and watch as over the next 10 -15 days your crystal will grow to its full size. Not only will you have a beautiful crystal to decorate your room with, it also glows in the dark!p>A fun home science project to encourage children's interest in geology. This crystal growing kit is a fantastic science activity for school holidays and quiet weekends.