Ideally, gemstones should be handled as little as possible; the more contact you have with them, the less good they look and the more you risk damaging them. A stone should be cleaned with a cloth prior to viewing, as grease and dirt can affect the brilliance and colour – diamonds can lose several colour and clarity grades as a result of accumulated grime. Gemstones should never be placed on a glass or metal surface because they can scratch easily there. Try to keep a white cloth handy as a protective covering – the white background will also display the full colour of the stone. Be careful when measuring stones, as they can pick up scratches from caliper and vernier gauges.
All gemstones and gem-set jewelry should be stored individually in boxes or bags. If you keep stones such as tourmaline or topaz together in a bag they will damage each other. Brittle and soft stones, including organic material, require extra care – they should be stored separately away from any heat sources or chemical contact. Ideally, rows of pearls should be wrapped in acid-free tissue paper rather than in plastic bags because the organic nature of the material is vulnerable to heat and condensation. Tissue paper allows air to flow around the pearls.
jewelry that is set with fragile stones is vulnerable to perfumes, lotions, household chemicals and detergents, so should be removed when showering, bathing or doing household cleaning. Metal polishes can also affect organic stones and gem materials such as opal and turquoise; the polish can be absorbed by the stone, which will then become discoloured or lose its lustre, Direct sunlight can inflict damage on jewelry that contains gemstones such as kunzite and amethyst and cause their colour to fade, while hot sunlight can dehydrate opal, leading to cracking and a loss of colour play.
Gemstones that are set in particular rings will need cleaning from time to time, because dirt can gather under the setting and affect the appearance of faceted stones. Simply soak the item in hot water with a dash of detergent and then clean gently with a toothbrush. Note that detergent shouldn’t be used with organic and porous gemstones.
If you hold a stone with your fingers, not only will you make it greasy and reduce the brilliance, you’ll also get only a limited view. Ideally you should use tweezers that are fine-tipped with serrated jaws; the slimmer they are, the greater the accuracy when picking up and placing the stone. The serrations prevent the stone from slipping and rotating, but don’t use this style of tweezers on softer, delicate material because the rough jaws could damage the surface finish of the stone. Over time, the serrations will wear down, especially if they’re used for hard gem material such as diamonds. The spring, or tension, in the tweezers can also be lost through misuse and become floppy. A temporary wedge made from folded paper will open up the jaws and bring back the tension. Always try to hold the stone by the girdle; if you hold it by the table and pavilion you may scratch the large table facet. Don’t squeeze the tweezers too hard or place too much pressure on the gemstone or it will pop out (and usually end up under the table or across the room). All that’s needed to keep the stone in place is a constant gentle pressure, which you will achieve with practice. In the meantime, a torch is useful for finding dropped gemstones.
USING A LOUPE
The best type of loupe is one with a triplet lens and 10 x magnifications. Some dealers prefer to use a loupe that has black housing around the lens rather than chrome so that the housing doesn’t affect the colour of the stone.
Hold the loupe between your thumb and forefinger and bring it about 1 inch (2.5 cm) away from your eye. with your hand resting on your cheek If using tweezers, place the stone face down on the tray, grip the girdle (outer edges) of the stone with the tweezers, and rotate at the wrist until the stone is face up. Bring the gemstone or jewelry toward the lens until it is in focus. To avoid shaking, put your elbow on the table. Illuminate the stone correctly so the light is angled into the stone and not in your eyes. Focus on both the surface and the interior of the stone.