Get Bedazzled: Profiles of Precious Stones
Diamonds, rubies, sapphires and emeralds – these magnificent gems are considered the four precious or cardinal gemstones, all other stones are traditionally regarded as semiprecious. This distinction should really be seen in a historical context, rather than a measure of value. The term was coined in the 1850s, to reflect the rarity and quality of certain stones.
There’s no denying that these four gems are deservedly famous, but it’s incorrect today to regard semiprecious stones as having less value. To see how imperfect this categorisation is, amethyst was on this original list and it has long been regarded as a stone of royalty. When huge deposits of this violet-coloured stone were discovered in Brazil, it was unceremoniously removed from this list, it lost its value and status. Additionally, Tanzanite, which is only found in a 4km square radius in northern Tanzania, and is both extremely rare and valuable, is not on this original list.
The gem trade is no longer making a sharp distinction between the two, but for the sake of tradition and simplicity, here are the profiles for diamonds, rubies, sapphires and emeralds.
Digging for Diamonds
Diamonds are by far the most popular gemstones – the king (or perhaps queen?) of rocks. They are also the only gems that are composed of one pure element: carbon. The most common material on earth, the basic building blocks of life and the same as the lead in your pencil.
Diamond comes from the Greek word “adamas”, which means “invincible”- appropriate as it’s the hardest natural substance on the planet. They take millennia to form and do so under incredible heat and pressure.
The first diamonds were discovered in India around 400 BC, and today half of the world’s diamonds come from central and southern Africa. Even though diamonds are highly valuable, they aren’t particularly rare.
Colour, Clarity, Cut and Carat
A diamond is graded according to the 4 Cs: colour, clarity, cut and carat. Each quality is important in its own right, and together they determine overall value. The other cardinal stones are treasured for their rich hues, but a diamond’s worth is in it being colourless. They do in fact come in a rainbow of shades, but these are called ‘fancy diamonds’ and are classified differently. Fancies are valued more on their colour then carat weight, which can make them more expensive than their colourless cousins.
Most diamonds have flaws, even if they seem invisible to the untrained eye. Flawless diamonds are exceptional, rare and pricey. The stones can be artificially enhanced but jewellery stores need to disclose all treatments. The most treasured stones have a crystalline clarity and they possess perfect cleavage (meaning that there exist specific planes that that have weaker atomic links within the diamond), so they can be split with one blow.
A cut diamond’s ability to reflect and refract light is incomparable in the mineral world, and technically these terms are referred to as fire and brilliance. The most popular cut is the brilliant cut, the most common shape is round, and the favoured setting is solitaire. Together these accentuate the features of a specific stone.
The Moh’s scale is a measure of mineral hardness from 1-10. Talc comes in at 1, a good steel file is 6.5 and diamonds are a perfect 10. They’re so hard they need to be cut using another diamond, but they’re not indestructible and can chip. To clean simply wipe them using warm soapy water. Ultrasonic cleaners are considered safe but be cautious with fragile settings.
According to the Greeks, they believed diamonds were splinters of stars that had fallen from the sky. In these ancient times their properties of clarity and hardness were seen as symbols of power, purity and longevity, and they were kept as amulets for healing. Diamonds today are regarded as the stones of marriage and commitment.
If your birthday is in April, or you’re celebrating a 60th or 75th wedding anniversary, I hope you’re lucky enough to receive this enduring symbol of commitment, and your own piece of starlight.
Reaching for Rubies
Rubies start off as dull, rather greasy looking stones, but once they’re cut and polished, they become one of the world’s most desirable coloured stones. These deeply red gems get their name from the Latin word “ruber”, meaning red, and in Sanskrit they were called “ratnaraj”, which is roughly translated as “king of gems”.
Burma (Myanmar) is considered the world’s best source of rubies. These stones have unparalleled clarity and the colour is – perhaps a little on the gory side – referred to as pigeon’s blood. Sri Lanka is another ancient supply of rubies, and they’re also found in Cambodia, Tanzania and Thailand.
Colour, Clarity, Cut and Carat
Rubies and sapphires come from the mineral corundum, but rubies are rarer. When chromium is present, the mineral becomes red and is called a ruby, all other colours of chromium are called sapphire. Rubies are always a shade of red, from pink to brown, but the most valuable is vivid red, with a suggestion of blue. The deeper the red, the rarer and more expensive the stone.
Clarity is not as significant as colour, and when it comes to inclusions, most natural rubies have them. It’s common to use heat treatments, dying and oiling to improve colour and clarity, but your jeweller needs to inform you of these enhancements.
Star rubies are when tiny inclusions cause asterism, a six-rayed star visible under certain light, and these are uncommon and prized. A ruby can also display pleochroism, which means that the colour changes depending on the angle you look at it.
The most intensely coloured and clear rubies are usually in a brilliant or step cut, so that they have a deep red glow. Rubies over one carat are unusual, and prices increase significantly as the stones get larger.
A ruby is pretty and tough, scoring a 9 on the Moh’s scale. Clean it with a soft cloth and warm soapy water, and if there aren’t too many inclusions, an ultrasonic cleaner can be used.
Red is the colour of passion and power, which is why this gem has long been considered the stone of love. It’s claimed to protect its wearer from injury, provide energy and courage, and bring good luck. In many cultures around the world, the ruby represents the sun, and according to ancient Oriental beliefs, the ruby has an eternal, inner flame, earning it the name glowing stone.
For centuries this gem has been considered the stone of royalty, it’s also the birthstone for July and the traditional anniversary gift for the 40th year of marriage. If you get the princely gift of a ruby, hang onto it with love and passion.
Searching for Sapphires
The celestial hues of sapphires have resulted in this beautiful gemstone being regarded as a symbol of heaven, and in fact, the Persians believed that the sky’s colour was a reflection of the sapphires on earth.
The name comes from the Latin “sapphirus” which means blue, and the most prized stones are the deep blue, cornflower gems from Kashmir. These have an intense, velvety colour and are highly sought after. Sri Lanka is another source of quality stones, along with Tanzania and Madagascar.
Colour, Clarity, and Cut
When most people think of sapphires, they imagine a blue stone, but this precious gem comes in an array of colours, from yellow to pink. Rubies and sapphires are actually closely related and come from the same mineral corundum. Red corundum is called ruby, while all other colours are known as sapphires. When the iron in corundum makes the stone blue, and it’s simply called sapphire, when it’s a different shade, the colour is included in the name – such as pink sapphire.
Sapphires come in every tone of blue, from pale to indigo, and it’s the colour that’s more important than size or clarity. Most natural sapphire is light blue, with heavy inclusions, and so, overwhelmingly, stones are heat treated to improve both colour and clarity. A striking feature of the stone is when it has ingrown fibrous inclusions that make a six-rayed star visible under certain light. This is called asterism and it increases the stone’s rarity and value.
These stones are beautiful but tough and can be cut into various shapes, including round, heart and emerald.
Sapphires are harder than rubies and are second only to diamonds on the Moh’s scale. They’re durable and should be cleaned in warm soapy water.
For centuries, sapphires have been favoured by royalty, because it was believed the stones symbolised power and strength but also kindness and wisdom. They were also popular with the clergy as they represented peace, devotion, truth and spiritual enlightenment. More specifically they were deemed to increase concentration, calm the mind and protect the wearer from poison, plague and sorcery.
Sapphires are the traditional gift on 45th wedding anniversaries and they’re the birthstone for September. If you believe in these metaphorical traits, then giving a sapphire will bring happiness to the wearer (not just from receiving the gift!), faithfulness and it will provide protection.
Exploring For Emeralds
The brilliant green emerald is irrefutably one of the most loved, coloured gemstones in the world. It’s thought that the oldest mines were near the Red Sea, dating back between 3000 and 1500 BC, and they were referred to as Cleopatra’s mines.
Columbia is the most recognised source of deep green stones, but they’re found around the world in Russia, Afghanistan and Zambia. Brazil has the rare emerald cat’s eye and the unusual Trapiche emerald, which looks like a six-rayed star.
Colour, Clarity, and Cut
The word emerald comes from the Greek word “smaragdos”, which means green stone. It’s the most precious stone in the beryl family and its colour is from chromium impurities. Emeralds come in a variety of greens, some with yellow undertones, but the most desirable is grass green, with a slight bluish tint. The value of an emerald is in its colour.
Clarity is graded by eye, and can vary from translucent to opaque, and it’s the transparent stones that are sought after. The flaws in emeralds aren’t considered negative properties, but rather signs that it’s natural, not manmade. They can’t be heat treated, or they lose their colour, but they’re routinely coated with oil, clear resin or paraffin, to fill cracks and deepen the colour.
The emerald cut is a well-known shape, and it was created for this specific gemstone. It’s a rectangular step cut, with angled corners, to amplify its beauty and colour, but also to prevent chipping.
Emeralds are rated a 7.5-8 on the Moh’s scale but because of their heavy inclusions, they’re considered fragile. Use warm water and a mild soap to clean, and avoid ultrasonic and steam cleaners which remove the protective coating.
Civilisations throughout history have adored this beautiful green gem. The Incas and Aztecs both considered it to be sacred and the ancient Egyptians believed it had special healing powers.
Because of its vivid colour, it’s associated with spring, hope, rebirth and peace. There’s also a close connection with Venus – the goddess of love and beauty – and it’s thought to aid in fertility. It’s believed the stone can cure depression, prevent insomnia and improving memory.
High quality emeralds are rare, which makes them treasured pieces of jewellery when given as a birthstone in May, and a present for a 55th wedding anniversary.
Blue, red, green or white, these exquisite gemstones are some of the most desirable rocks on the planet. Whether you wear them as an engagement ring, a solitaire necklace or pendant earrings, these beautiful stones are indeed precious!