Gemstone jewellery is an investment of money and emotion. Proper care extends the life and beauty of every piece, but "proper care" is not universal. Different stones have radically different physical properties, and a cleaning method that is safe for one gem can damage another.
Hard Stones: Diamonds, Rubies, Sapphires
Stones with a Mohs hardness of 9 or higher are the most resilient. Diamonds, rubies, and sapphires can be cleaned with warm soapy water and a soft toothbrush. Ultrasonic cleaners are generally safe for untreated diamonds and corundum, but should be avoided for treated or included stones. Steam cleaners are safe for untreated diamonds but risky for corundum with significant inclusions, as rapid temperature changes can cause fractures.
Medium Stones: Topaz, Aquamarine, Tourmaline
Stones in the 7 to 8 Mohs range are suitable for everyday jewellery with care. Warm soapy water and gentle scrubbing work well. Avoid ultrasonic cleaners for tourmaline (especially watermelon tourmaline) and any stone with visible inclusions. Topaz has perfect cleavage in one direction, meaning a sharp impact can split the crystal cleanly in two. Store topaz pieces separately and avoid wearing them during physical activities.
Soft and Delicate Stones: Emerald, Opal, Pearl
Emeralds are almost always oiled or resin-filled to improve clarity. Ultrasonic cleaning, steam cleaning, and even prolonged exposure to warm water can strip this treatment, making the stone appear cloudier. Clean emeralds only with a damp cloth. Opals contain up to 20% water and can crack ("craze") if they dry out. Never expose opals to heat or prolonged direct sunlight. Store them in a slightly humid environment. Pearls are organic and porous. Perfume, hairspray, and even skin acids attack the nacre surface. Put pearls on last when getting dressed, and wipe them with a soft cloth after every wearing.
General Storage Rules
Store each piece separately or in individual soft pouches. Harder stones will scratch softer ones if they come into contact. Keep jewellery away from direct sunlight, which can fade amethyst, rose quartz, and kunzite over time. Remove rings before washing dishes, gardening, or exercising. Have clasps and prong settings checked by a jeweller annually, since a worn prong is the leading cause of lost stones.
Need a gemstone certified?
Contact GTCL
