Green Tourmaline on Quartz Matrix - Unique #12 Green tourmaline is a special crystal prized for its spectacular colour. The green tourmaline crystals on this piece encrust the quartz matrix. They also form their signature green crystal rods, with several holes in the piece where some crystals used to grow. This specimen is a very interesting piece of geological art to have for display and admiration. Note: This crystal specimen is brittle/fragile and should be handled with care.