Gemstones
Opals
Opals are irresistible beautiful, but at the same time quite delicate. An opal is a gemstone made from tiny spheres of hydrated silica. Unlike crystals such as diamond or sapphire, opal has an amorphous structure, meaning its atoms aren’t arranged in a regular crystal lattice. That unusual structure is what creates opal’s famous “play of colour”, where flashes of rainbow colours appear as the stone moves.
Australia produces the majority of the world’s precious opal, especially from places like Lightning Ridge, Coober Pedy and Winton.
Main types of opal:
Precious opal – shows colourful flashes (“play of colour”)
Black opals from Lightning Ridge are among the world’s most expensive gemstones.
Common Opal– No play of colour. Can still be attractive in blue, pink, green or white shades.
Fire Opal– Often orange, red, or yellow; may or may not show play of colour. Most famously associated with Mexico.
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. Avoid harsh impacts and store separately from harder gems.
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.
Pearls are organic gemstones formed inside certain mollusks – mainly oysters and mussels – when an irritant becomes coated with layers of cacre.
The beauty of a pearl depends entirely on the quality of its nacre, 2.5-4.5 on the Mohs scale (extremely soft and prone to scratching)
While natural pearls are incredibly rare and found by chance, most pearls on the market today are cultured, meaning human intervention initiated the pearl-forming process.
Main types of pearls
Akoya pearls- known for high luster and perfectly round shapes; typically, white or cream. Typically produced in Japan.
South Sea pearls- large pearls with satin-like luster; colours include white, silver and gold. Mainly from Australia.
Tahitian pearls- Famous for dark colours: black, green, peacock, grey. Produced in French Polynesia.
Fresh water Pearls- produced in Rivers/Lakes, produced in higher volumes; come in a vast array of shapes (baroque) and pastel colours.
Pearl care tips
- Pearls are softer than many gemstones
- Avoid perfume, hairspray and harsh chemicals. Never expose your pearls to chlorinated water. Avoid contact with detergents, make up and perspiration. These will tarnish the luster 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.
- Store separately to prevent scratches.
- You should have them restrung once a year with new silk thread and best have them knotted to be on the safe side.
Pearl is the primary birthstone for June and the traditional gift for 3rd and 30th wedding anniversaries.
Follow these simple rules and your pearls will last a lifetime.
Emerald
Emerald is the most famous member of the beryl family. While other beryls like aquamarine and morganite are valued for their clarity, emeralds are prized for their intense, lush green colour, which is caused by trace amounts of chromium, vanadium, and iron.
Most emeralds naturally contain inclusions called “Jardin” (Garden in French)
Major sources include:
- Colombia- especially the Muzo, Chivor and Coscuez mines , known for vivid green stones.
- Zambia- often slightly darker with bluish tones.
- Brazil
- Afghanistan
Most emeralds are treated with oils or resins to improve clarity. This is standard in the gem trade.
Despite their relatively high hardness, emeralds are quite brittle. Their internal fractures make them susceptible to damage from physical impact or pressure. Avoid ultrasonic and steam cleaners, exposure to harsh chemicals, perfumes, use only a very soft brush and look warm mild soapy water.
Emerald is the traditional birthstone for May, has a hardness of 7.5-8 on the Mohs scale and the gemstone for the 20th and 35th wedding anniversaries.
Ruby
Ruby is the red variety of the mineral corundum, one of the most valuable and historically significant gemstones in the world. All other colours of gem-quality corundum are classified as sapphires.
The value of a ruby is primarily determined by its colour, followed by clarity, cut, and carat weight. The most prized shade is often called “pigeon blood red”. Hardness 9 on the Mohs scale, making ruby one of the hardest gemstones after diamond.
Major ruby sources include:
Myanmar, Sri Lanka, Thailand, Mozambique, Madagascar
Rubies often contain “silk” (slender needles of rutile). When these needles are dense and intersect, they can create a six-rayed star effect known as asterism, resulting in a “star ruby”.
Ruby is the traditional birthstone for July and is used to commemorate 15th and 40th wedding anniversaries.
Peridot
Peridot is a bright green gemstone of the mineral olivine. Its colour ranges from yellow green to deep olive green, caused by iron within the crystal structure. Unlike many gems, peridot usually appears in only shades of green.
Though it is known as the “Evening Emerald”, due to its high double refraction, peridot often appears to glow under artificial light, earning it this nickname in the ancient world. Peridot was mined as early as 1500BCE on Topazos island (now St. John’s Island ) in the Red Sea. Historians now believe that many of Cleopatra’s famous “emeralds” were actually peridots.
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.
Peridot is the traditional birthstone for August and the gemstone used to celebrate 15th wedding anniversaries.
Sapphire
Sapphire is a variety of the mineral corundum. Most sapphires are blue, but they also occur in pink, yellow, green, purple, orange, white and black. Red corundum is classified separately as ruby.
Sapphires are among the hardest natural gemstones, second only to diamond on the Mohs hardness scale.
Famous sapphire colours:
Blue sapphire- The most famous variety, especially deep “royal blue” stones.
Fancy sapphires- Any sapphire that is not blue is often called a “fancy sapphire”
A rare orange-pink variety called padparadscha sapphire is especially valuable.
Star sapphire- Some sapphires show a star shaped light effect called asterism due to tiny needle like inclusions.
Major sapphire sources:
Sri Lanka, Kashmir, Myanmar, Madagascar and Australia
Sapphire is the birthstone for September. Because sapphires are durable, they are suitable for daily wear.
Tourmaline
Tourmaline is a large family of colourful minerals, prized both as gemstones and collector crystals. It’s famous because it occurs in almost every colour naturally- from deep black to neon blue, vivid green, pink, and multi coloured combinations.
Popular varieties:
Black Tourmaline (Schorl)- the most common type
Watermelon Tourmaline-
pink center with green outer rim. Highly collectable and often expensive.
Paraiba Tourmaline-
Famous electric neon/blue green glow. Among the most valuable tourmalines.
Rubellite Tourmaline-
pink to red variety, often confused with ruby.
Tourmaline has a hardness of 7-7.5 on the Mohs scale and is one of the official birthstones for October, alongside Opal.
Quartz
Quartz is one of the most common minerals on Earth. Common varieties:
- Clear quartz- transparent crystals
- Rose quartz- pink variety
- Amethyst- purple quartz
- Citrine- yellow/orange quartz
- Smoky quartz- brown to black
- Agate & chalcedony- microcrystalline quartz forms
Gem quality quartz is widely used in jewellery.
Amethyst is the purple variety of Quartz and 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.
Different types include:
- Deep purple amethyst-highly valued, rich colour.
- Rose de France- pale lilac variety
- Ametrine- natural mix of amethyst and citrine in one crystal.
Amethyst has a hardness of 7 on the Mohs scale, relatively hard and durable for everyday jewellery.
Chrysoprase is a rare variety of chalcedony. Its considered one of the most valuable chalcedony gemstones.
Australia is especially famous for high-quality chrysoprase, and some of the world’s best material comes from Western Australia.
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.
Aquamarine
Aquamarine, the “Gem of the Sea” is a captivating light blue to teal- blue, transparent gemstone of the mineral beryl.
Historically, Aquamarine has been deeply tied to the ocean. “The sailors stone”, ancient Greeks and Romans carried it as a protective talisman to ensure safe passage across stormy seas and to prevent seasickness. Today, it is a symbol of tranquillity, serenity and clear communication.
Best for those who love high-clarity jewellery and a “cool” colour palette.
As the birthstone for March, it has hardness of 7.5-8 on the Mohs scale, making it suitable for everyday wear, including rings.
Aquamarine comes in a fantastic variety of sizes, commonly cut oval, round, emerald and pear shapes; often used in rings, pendants and earrings.
Though tough, Aquamarine can be damaged by harsh chemicals or extreme heat.
Avoid ultrasonic cleaners or steam cleaners, as they can cause stones with natural mineral inclusions to shatter. Store your aquamarine jewellery separate from harder gems like diamonds or sapphires, which can scratch the surface.
Use warm water, mild dish soap and a soft brush to clean your Aquamarine jewellery.
Fancy colour Diamonds
Diamonds have long been celebrated for their classic, colourless sparkle.
While colourless diamonds are iconic, the natural world holds an even rarer, more vibrant secret: Fancy Coloured Diamonds
Think warm, buttery yellows that radiate joy; delicate blush pinks for an elegant touch; and the deep, mysterious allure of teal or chocolate brown. These exceptional gems don’t just sparkle ; they tell a story in colour.
Champane diamonds are a sophisticated category of natural fancy – coloured diamonds characterized by their warm, golden-brown hues. They offer a unique, earthy alternative to traditional colourless stones and have become increasingly popular for bespoke and vintage – inspired designs.
They are often graded on a scale (frequently the C1-C7 Argyle scale) to describe their depth:
Pink diamonds are among the most mysterious and coveted gemstones in the world.
Until its closure in late 2020 , the Argyle Mine in Western Australia produced over 90% of the world’s pink diamonds . Since the mine closed , no new primary source has been discovered that matches Argyle’s volume or colour intensity . This has transformed pink diamonds from a luxury purchase into a high- value “legacy” asset.
While white diamonds are graded on a D-to-Z scale, pink diamonds use a specialized colour intensity scale. The deeper the colour , the more exponentially the value rises.
Yellow diamonds are some of the most vibrant and sought after fancy-coloured gems. Their “sunny” disposition makes them a favourite for those seeking an alternative to colourless diamonds that still offers a classic, timeless feel.
Yellow diamonds are unique because they exist on both the standard D-Z scale and the Fancy colour scale.
The “Cape “ Range : Diamond graded U through Z are technically colourless diamonds with a heavy yellow tint. They are often more affordable and look beautiful in yellow gold.
The “Fancy “ Range : Once a diamond’s colour is stronger than a “Z” masterstone, it enters the Fancy Colour scale: Fancy Light /Fancy/ Fancy Intense / Fancy Vivid / Fancy Deep
Grey diamonds – often referred to as “Silver” or “Cloud” diamonds – have become a breakout favourite for those who love a moody, sophisticated and alternative aesthetic. They sit perfectly between the classic brilliance of a white diamond and the edgy depth of a black diamond.
There are two types of grey diamonds:
Fancy Grey Diamonds: These are high clarity stones where the grey colour is uniform throughout the crystal.
Salt and Pepper Diamonds: These are diamonds with a high concentration of dark and white inclusions , giving them a speckled , “galaxy like “ grey appearance. These are incredibly popular for rustic or bohemian engagement rings.
Did you know that for every 10,000 colourless diamonds mined , only one will have enough natural colour to be called “Fancy”?