Although gemstones are among the most durable of substances, they do need some care. Following a few general rules will make sure that they last for generations still looking like the day you bought them.

• Stones that have a Moh’s hardness of less than 8 are highly subject to scratching; harder stones are less likely to be scratched but are still subject to chipping and fracture. Remember that quartz, with a hardness of 7, is one of the most abundant minerals on earth, in the form of sand, or silica. When removing dust from soft stones, it's usually best to rinse them with clean water and dry with a soft cloth. Also, store jewelry and loose gems in separate padded compartments or wrapped in soft lint free cloth to prevent scratching, chipping, and entanglement.
• When cleaning nonporous gemstones, washing gently with a weak solution of ammonia, rinsing with clean lukewarm water, and drying with a soft lint free cloth is quite effective and safe. Just be sure to plug the sink so you don't wash your stones down the drain! On stones harder than quartz (Moh's hardness of 7), it's safe to do a little gentle scrubbing with a soft toothbrush, but if you're cleaning jewelry, be careful not to scrub highly polished metal surfaces, as the slight abrasive action of the brush will produce slightly hazy effects on the metal. A little soaking may be necessary to remove heavier deposits.
  
• If you use hand lotions or creams, remove your jewelry before applying them! This will help prevent heavy buildup of dirt and oil around your gemstones. Also if you plan to do heavy or dirty work with your hands, remove your jewelry so they will not be subjected to harsh blows, abrasives, or unnecessary dirt.
  
• Pearls, Coral and porous stones such as Opal, Turquoise, or Malachite should be kept away from dirty water and oils to avoid discoloration. Wipe them gently with a soft, damp cloth. Do not wear your jewelry especially rings containing these stones while washing dishes or similar activities.
  
• Opal, Pearls, Coral, Turquoise and many collecting gems are quite heat sensitive (both to extremes and to sudden changes in temperature). Do not leave them sitting in hot sunlight, near radiators, or in hot cars. Once an Opal begins to craze, it's usually unsalvageable. Opals require special care. Never use an ultrasonic, never use ammonia, and avoid heat and strong light which can dry out the water in Opals.
  
• Sharp corners, such as the tips of pear shapes and marquise cut stones, are especially susceptible to breakage and should be protected by the setting. Also, faceted stones with shallow crown angles (generally 30 degrees or less), and thin or uneven girdles are particularly prone to chipping and need extra protection.
  
• Always store bead necklaces (such as Lapis, Pearls, Coral etc) flat as silk stretches over time.
  Store each piece of gemstone jewelry separately so that harder stones don't scratch softer ones. Almost every gemstone is much harder than the metal it is set in. Gems can scratch the finish on your gold, silver or platinum if you throw your jewelry in a heap in a drawer or jewelry box. Below you find a chart to care for your most common gemstones.

Gemstone Maintenance Chart