28th March 2018 Guides
This is part 3 from our series of guides to birthstones which gives an overview on July, August, September. To read part one click here. Birthstones are a fantastic way to add a special meaning to jewellery and make great gifts to mark a birthday, anniversary, graduation or other memorable occasion. They can be incorporated into rings, necklaces, pendants, bracelets and more. Paired with diamonds, they can add a splash of colour and variety to your jewellery piece. So read up on all the birthstones with our handy guide:
The name “ruby” comes from rubeus, the Latin word for red. In ancient Sanskrit, ruby translated to ratnaraj, which meant “king of precious stones.” These fiery gems have been treasured throughout history for their vitality and if famed for it’s fiery red colour. Tough and durable, ruby measures 9 on the Mohs scale. Diamond is the only natural gemstone harder than ruby.
When purchasing a ruby, like diamonds, rubies are evaluated using the 4Cs, plus size and geographic origin. The most important feature of a ruby is its red colour, as other hues of this gem species are considered sapphire. The finest ruby is a vibrant purplish red, losing value (and classification as a ruby) as it leans toward brown, orange or even pink. All natural rubies contain imperfections, like rutile inclusions called “silk.” These can actually increase the value of ruby (when displaying a rare cat’s eye or star effect) and are often used to determine a gem’s authenticity. Rubies also require good transparency. Opaque rubies are much less valuable, even if they display cat’s eye or asterism.
The original birthstone for August was Sardonyx, and then peridot was added, becoming August’s primary gem. More recently however, spinel was added to the line up.
Also known as “the Evening Emerald” because its sparkling green hue looks brilliant any time of day, peridots are said to possess healing properties that protect against nightmares and evil, ensuring peace and happiness. Peridot only measures 6.5 to 7 on the Mohs scale, so while the raw crystal is prone to cracking during cutting, the finished gemstones are fairly robust and easy to wear. When buying peridots, look for a lovely lime green hue without any hints of brown or yellow. Quality gems have no inclusions visible to the naked eye, though dark spots may be evident under a microscope. When you look closely, due to double refraction, you may see two of each facet on a peridot.
Sardonyx makes a great gift for people born in August who want something a little different than the traditional peridot birthstone. Readily available and relatively inexpensive, sardonyx makes an affordable addition to anyone’s collection. The qualify factors of sardonyx are not as clearly defined as other gems like diamonds, so ask for help when selecting good stones. Generally, however, the 4Cs still apply.The most attractive sardonyx shows a high contrast between reddish layers of sard stone and white bands of onyx. It may be translucent or opaque, seldom showing flaws or fractures.
Although sapphire typically refers to the rich blue gemstone variety of the mineral corundum, this royal gem actually occurs in a rainbow of hues. Sapphires come in every colour except red, which earn the classification of rubies instead. When purchasing a sapphire, colour is the key indicator of a sapphire’s price. The highest valued sapphires are vivid blue, sometimes with a violet hue. Secondary hues of green or grey detract from sapphire’s value. Blue sapphires typically have better clarity than rubies, though they often have long, thin rutile inclusions called “silk.” Inclusions generally make gems less valuable, but they can actually increase the value of sapphires that exhibit asterism. Blue sapphires can range in size from a few points to hundreds of carats. Most commercial-quality blue sapphires weigh less than five carats. Large blue sapphires, while rare, are more readily available than large rubies.
If you’re interested in sapphires, check out our collection of blue sapphire and diamond rings here.
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