Care of Precious Gems
Valuable stones set in jewellery are not infrequently lost through the claws or settings becoming loose. Claws, especially in rings, wear thin with use. An accidental knock or catching on clothing can break them off.
The settings should be examined regularly with a magnifying glass. If they are very thin, bent outwards or twisted, take them to a jeweler for repair right away.
Overtightening the claws can set up internal stresses which may cause a fracture to appear in the gem weeks or even months later. Opal doublets and even solid opals are especially subject to such damage, as are emeralds, topaz, zircons and even diamonds.
Do not try to repair fine antique jewellery. This is very much a specialist's job.
Transparent gems lose their lustre and brilliance when dirt accumulates in the setting. This happens very quickly during dishwashing; diamonds are particularly prone since they attract grease.
A tough scum caused by hand lotions, emulsified grease, soap and washing-up liquids is deposited behind the gem. Break up this scum with a sharpened matchstick.
A small stiffish brush can be used to dislodge persistent scum, but do not use needles or metal points.
Then wash in fairly hot water with some ammonia and detergent.
Rinse well in hot running water. Finish by dipping the article in methylated spirits and laying it on paper tissue to dry.
Do not mix up jewellery loosely in a jewel case. Wrap items separately in soft, clean tissue paper. Diamonds especially will scratch other gems. If the table (the flat top surface) of a gem is badly scratched or chipped, consult a jeweler about having it recut.
Opals, turquoise and lapis lazuli are all fairly soft and prone to scratching. If damaged they can sometimes be repolished without complete recutting . Consult a jeweler. Opals and turquoise are also partly porous and should not be immersed in dirty or greasy water or oil. If they are in a ring, remove it before washing up or using hand lotions. Badly stained turquoise loses its fine color and can never be cleaned properly.
Emerald is brittle-the corners and facet edges tend to chip with only a moderate knock on a hard surface, so take off rings when engaged in gardening or rough housework. Zircons are also subject to facet-edge chipping.
Amethysts and zircons should not be exposed to bright sunlight for prolonged periods, as some of them are subject to color fading. Pearls may be stained by grease from cosmetics or skin acids- the stain is carried inside the pearl along the string. Do not apply hair spray while wearing pearls.
Check the clasp and string regularly; renew or repair as required. Wrap them in soft, fresh tissue when not in use. Scent sprays can damage the lacquer on some imitation pearls. Take them off before using the spray.
Precious gem-set jewellery should be fully covered by insurance against loss, burglary or damage. Have them identified and appraised by an expert.