Gemstones
Opals
Opals are irresistable beautiful but at the same time quite delicate. Opals vary in optical density from opaque to semi-transparent and show a form of iridescence.
Black opals are the rarest, whereas white and greens are the most common.
Most noteworthy, opals are very sensitive to pressure and thermal shock (hot or cold), which causes crazing (surface cracking). Hence, this soft and fragile gem requires special care.
Opal is the birthstone for October and has a hardness of 5 1/2 – 6 1/2 on the Mohs scale.
“Pearls are always appropriate “
Jackie Kennedy
Pearls
Perhaps the most beloved gem of all time. Pearls have been worn from the beginning of time and adorned by the noble, the rich and the famous as their favourite accessory item. They always look very elegant and can be worn with almost anything. Today everyone loves to wear pearls and here in Australia we are blessed with the best and highest quality available anywhere in the world.
How to take care of your pearls
Always store pearls separately to your other jewellery items in a slightly moist linen cloth to prevent them from drying out in low humidity atmospheres.
Never expose your pearls to chlorinated water. Avoid contact with detergents, perfume, make up and perspiration. These will tarnish the lustre and will reduce the life of your pearls.
Remember to wipe your pearls down with a soft cloth after each wear.
Pearls should be worn on clean dry skin. Wear your pearls as much as possible as the oil of the skin improves their lustre. You should have them restrung once a year with new silk thread and best have them knotted to be on the safe side.
Follow these simple rules and your pearls will last a lifetime.
Emerald
The Precious Gemstone Emerald is of the green variety of Beryl. It is the most famous and valuable green gemstone. Its beautiful green colour, combined with durability and rarity, makes it one of the most expensive gemstones.
Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor. Though Emerald has good hardness, it’s a brittle stone. It may develop internal cracks if banged hard or if subject to extreme temperature change. Emerald is the birthstone for May and has a hardness of 7.5–8 on the Mohs scale.
Ruby
Ruby is distinguished for its bright red colour, being the most famed and fabled red gemstone. Beside for its bright colour, it is a most desirable gem due to its hardness, durability, luster, and rarity.
Transparent rubies of large sizes are even rarer than Diamonds. Ruby is the red variety of the mineral Corundum and has a hardness of 9 on the Mohs scale.
Peridot
Peridot is a gem-quality variety of the mineral olivine. Thus, peridot is found only in green. In fact, peridot is one of the few gemstones available that can be found only in one colour, although the shades of green may vary from light yellowish to dark brownish-green
Peridot rates 6.5 to 7 on the Mohs hardness scale. It has fair to good toughness and is durable enough for jewellery wear but should be worn with some care so as not to scratch it or subject it to hard blows that can fracture it.
Sapphire
Sapphire is the most precious and valuable blue gemstone, a variety of the mineral corundum.
It is a very desirable gemstone due to its excellent colour, hardness, durability, and luster. The most desired colour is a pure cornflower-blue. They come in every colour of the rainbow. Except red. Sapphire has a hardness of 9 on the Mohs scale.
Tourmaline
Tourmaline has a variety of exciting colours with one of the widest colour ranges of any gem species, occurring in various shades of virtually every hue. Scientifically, tourmaline is not a single mineral, but a group of minerals related in their physical and chemical properties. The most commonly encountered colours are the wide variety of pink and green Stones that are pale in colour or have secondary colours of brown or salmon are not considered with high.
Tourmaline has a hardness of 7-7.5 on the Mohs scale.
Amethyst
Amethyst is the purple variety of the mineral Quartz and its most valuable and prized variety. Its name derives from the Greek “amethystos”, which means “not drunken”, as Amethyst in antiquity was thought to ward off drunkenness.
Colour is the most important. Amethyst colours range from pale lilac to deep reddish purple and ranging from transparent to translucent quartz. The finest amethyst is a deep purple colour with minimal colour zoning and it looks the best in daylight.
Amethyst has a hardness of 7 on the Mohs scale.
Garnet
Garnets are a group of silicate minerals that have been used since the Bronze Age as gemstones and abrasives. All species of garnets possess similar physical properties and crystal forms but differ in chemical composition.
Garnets come in a variety of colors and have many different varieties. However, the most widely-known color of Garnet gemstones is dark red but green tsavorite & demantoid are the rarest and most valuable.
Garnets are hard, durable and brilliant and are valued on carat weight, colour, cut and clarity. Garnet has a hardness of 7– 7.5 on the Mohs scale.
