Buying Coloured Gemstones
Care of Gemstones
All gemstones vary considerably in hardness, toughness, cleavage, reaction to heat, light and acids. Therefore, in order to preserve the beauty and durability of any given gemstone it is important to understand these factors.
In most cases, the full brilliance of a gemstone can be restored simply by using a mild detergent in warm water with a soft brush (not a toothbrush).
Although most commercially prepared jewellery cleaners are safe, care should be exercised when using cleaners that contain ammonia or harsh chemicals.
The key area when cleaning any transparent faceted gemstone is the pavilion since this area invariably collects dirt due to the setting.
Cleaning Procedure
Soak the gemstone for a few minutes in the cleaning solution.
Gently scrub the gemstone using a soft brush and ensure that any dirt collecting at the back of the setting is removed. Dip the gemstone back in the solution. Rinse under warm water. It is very important that the temperature of the water be the same as the solution to avoid "Thermal Shock". Shake or blow on the item (Do not use a hairdryer). Gently polish the gemstone with a soft lint-free cloth. To avoid liquid stains, some jewellers immerse the jewellery in a bed of dry maple wood chips.
Mechanical Cleaning
Includes "Ultrasonic Cleaning" and "Steaming".
All mechanical methods of cleaning are dangerous. Watch particularly for inclusions or stones with pronounced cleavage.
Ultrasonic Cleaning
Consists of a stainless steel tank with millions of microscopic frequency waves. These frequency impulses concentrate on the hardest element in the liquid.
Ultrasonic cleaners should never be used on treated stones such as Emerald, Ruby and Sapphire or on stones that are considered fragile such as Opal, Pearl, Emerald, Tanzanite, Coral, Turquoise, Malachite or Amber.
It is important to ensure that the gemstone or piece of jewellery is not in contact with the bottom or sides of the cleaner. Vibration can cause damage to the stones or scratch the jewellery.
All settings should be checked before putting them into the cleaner since the gemstones can become dislodged during cleaning.
Steam Cleaning
Steam cleaning is a very effective way of cleaning gemstones. However, care should be exercised so as not to cause thermal shock.
Tips
Always properly prepare any gemstone that is going to be heated by any of the aforementioned mechanical methods by gently warming the gemstone. Similarly, after heating, allow the gemstone to return gradually to room temperature by soaking in a warm water solution.
Inclusions, especially mineral, liquid or gaseous inclusions, can react differently when the gemstone is heated.
After wearing jewellery that has been in contact with the skin, always wipe the jewellery before storing it separately.
Pearls
Pearls have a predictable life span of 150 to 200 years if properly cared for.
Cleaning and Care
Always use a mild detergent in warm water. Never use anything harsh to remove stains from pearls. Do not immerse a strand of pearls in the solution since this can result in moisture entering the drilled hole and cause discolouration of the pearls. It can also cause deterioration of the "Silk" or "Nylon" thread. All pearls should be knotted to avoid abrasion and loss of pearls should the thread break.
Using an eye loupe and toothpick, gently remove any dirt that collects in the knots. Dry the pearls on a lint-free towel. Blow any excess moisture from knots and drilled holes. Do not use a hairdryer. Lay the pearls on an absorbent towel to speed up the drying. Always insist on silk. Although it will deteriorate faster, it does not attract dirt or grime and will not stretch.
Depending on how often the pearls are worn, have them restrung on a regular basis. Store them separately from other jewellery in a moisture free environment. Avoid sealed plastic bags.
Opals
Opals are soft and highly sensitive to "Thermal Shock". They also react to acids and alkalis. Because of there low hardness, they are easily scratched and should not be stored with other jewellery.
Opals also contain up to 30% water. Changes in temperature, can cause this to expand or contract. Heat can cause the water to evaporate resulting in a diminished play of colour.
Soak in oil or water if this occurs since this can restore the play of colour to an opal. Store opals in soft moist cotton to preserve their play of colour. Clean using the warm mild detergent and soft brush method. Avoid wearing opals on the pinkie finger since they are liable to sustain damage. Choose a setting that protects the stone. Avoid bezel settings which exert pressure on the opal.
ALWAYS REMOVE JEWELLERY WHEN SWIMMING IN A SWIMMING POOL. CHLORINE DISSOLVES GOLD AND CAN CAUSE SETTINGS TO WEAKEN OR STONES TO FALL OUT.
