A “drusy” gem is a gemstone with its surface covered in thousands of tiny, individual crystals. The drusy quartz is the most common type of drusy gem and its earth tones and pastel colors are highly coveted. Drusy quartz is more durable than other drusy gems because quartz is a hard substance. Quartz may be cleaned with mechanical tools or strong chemicals. The most common substances removed from quartz are hard white mineral coatings and iron stains. Special care must be used in cleaning drusy quartz to prevent its tiny crystals from breaking off.
Clean the tiny crystals on the surface of the drusy quartz with unscented dishwashing detergent, water and a soft brush. If stains or coating are found on another part of the quartz, then use the steps below to clean the other parts of the stone.
Use a spot-cleaning gun, which cleans with a high-pressure water spray, to clean the surface of the quartz. If the surface of the quartz still isn’t clean, use a tougher mechanical cleaning technique listed in steps 3 and 4.
Use an air abrasive tool, which blasts a stream of high pressure air with abrasive materials that act as a scouring powder. For quartz, tiny glass beads are best as the abrasive material because they are softer than the quartz. Do not use crushed glass, garnet sand or quartz sand, because they will damage your quartz. Use 80 pounds of pressure to start.
Use an air scribe, which is a small, hand-held jackhammer that uses air pressure to clean. An air scribe is the size of a marker or thick pencil.
Remove iron stains from your quartz with chemicals, if you do not have access to mechanical cleaning tools. Iron stains are caused by the minerals hematite and goethite and can be removed by soaking in a solution of sodium dithionate, oxalic acid, or hydrochloric acid.
If your drusy quartz is set in jewelry, then clean according to step 1. If your drusy quartz is in its natural stone form, then follow the other steps to clean the rest of the stone.
Drusy quartz can be used in pendants and earrings, but not rings or bracelets because of the risk of breaking the tiny crystals.
Try using the solution of sodium dithionate, also known as “iron out,” before you try the other acids. Oxalic acid and hydrochloric acid are corrosive and poisonous. Research the proper use and disposal of these acids, as well as safety procedures for using acids such as respiratory, eye and skin protection.