While most months are traditionally associated with one gemstone – September with sapphires, for example – October is one of the few that has two birthstones. Opal and tourmaline are two very different gems, offering those born in October a choice – over which speaks most to their unique tastes.
The Qualities Of Opal
Iridescent and often with a milky tone, opals have been considered bringers of good luck since the Middle Ages. Opal is the product of seasonal rains that drenched dry ground in regions such as Australia’s semi-desert “outback.”
Best known for its flashing rainbow colors called play-of-color, there are two broad classes of opal: precious and common. Precious opal displays play-of-color, common opal does not. Opal hues can range across the spectrum; an opal might display a single color, two or three colors, or all the colors of the rainbow.
The colors each stone can reflect depend on how it was formed – what the temperature was, what type of rock it was surrounded by, etc. These conditions affect the internal structure of the gemstone, allowing it to reflect certain colors and saturations. Opal can appear in many colors, including white, blue, pink, green, yellow, brown and black.
Opal engagement rings and jewelry often appeal to those with vintage, somewhat quirky tastes. As an October birthstone, they are an ideal birthday gift at this time of year; however, they can suit almost anyone. Their unique reflections of color offer a wide range of precious gemstone jewelry, from oversized gemstone rings, to delicate and understated bracelets. An opal engagement ring is a stunning offering of love and commitment.
The “Aurora Australis” was found in 1938 at Lightning Ridge in New South Wales, Australia, and is considered the world’s most valuable black opal. The oval, cut and polished stone has a harlequin pattern with dominant red, green and blue colors against a black background, which clocks in at 180 carats.
“Flame Queen” Opal is the most famous and best-known example of “eye-of-opal,” an eye-like effect created when opal fills a cavity, which looks like a fried egg. The Flame Queen weighs 263.18 carats and was also discovered at Lightning Ridge in New South Wales, Australia. Like all opals, the Flame Queen changes color depending on the lighting and angle of view. In 2003, Flame Queen was put up for auction at Christie’s in New York for an estimated price of $250,000.
Other Famous Opals
- The Halley’s Comet Opal (the world’s largest uncut black opal)
- The Pride of Australia Opal (often known as the Red Emperor Opal)
- The Andamooka Opal (presented to Queen Elizabeth II, also known as the Queen’s Opal)
- The Red Admiral Opal (sometimes known as the Butterfly Stone)
- The Black Prince Opal (originally known as the Harlequin Prince Opal)
The Beauty of Tourmaline
A crystal mineral, tourmaline is formed in a wide variety of colors. Blue, green, and red tourmaline (also called rubellite) are the most popular types used in gemstone jewelry. The pink and red hue is often produced through natural irradiation, deepening their color to an appealingly romantic shade. Tourmaline is typically mined in Brazil and Africa, although it can be formed in countries from the US to Sri Lanka.
Tourmaline is the most colorful of all gemstones, occurring in various shades of virtually every hue. The most common colors of Tourmaline are chrome (green), cat’s eye (striped brown), paraiba (bright neon blue), schorl (black), dravite (yellows and browns) and watermelon (green on the outside and pink on the inside).
Tourmalines grow in long, pencil-like crystals. Gem cutters aim to preserve as much of the rough stone as possible, often cut into long bars, octagons or baguettes. Tourmaline is highly sought after because combines good hardness (7 to 7.5 on the Mohs scale) with excellent durability.
Rubelite (red Tourmaline) is associated with compassion, comfort, safety and relaxation. Historically, it was believed to reflect kindness, tolerance and femininity. Tourmalines are also believed to be useful in relaxing the body and the mind, and to help in the treatment of many different diseases such as anxiety, blood poisoning, arthritis, and heart disease. Pink, of course, has long been associated with feminine style. If someone you love has a birthday in October, and adores the romantic look of pink and red gemstones, tourmaline is the right choice for a jewelry gift.
Varieties of Tourmalines
Tourmaline is actually a group of minerals and is a general term used for related gemstone varieties, which are typically classified according to their color. Here are a few commonly used tourmaline trade names:
Achroite – Very rare colorless or almost colorless tourmaline.
Dravite – Yellow-brown to dark-brown magnesium tourmaline. Intense, forest-green gems are also known as “chrome tourmaline” or “chrome dravite”.
Indicolite – Blue tourmaline.
Paraiba – Light-blue, blue-green, vivid blue or green copper tourmaline, named after the state in Brazil where it was found.
Rubellite – Intensely colored, red, pinkish-red or violet tourmaline.
Schorl – Black iron tourmaline.
Siberite – Lilac to violet-blue tourmaline, named after a deposit in the Urals.
Verdelite – Green tourmaline.
Buergerite – Iron tourmaline named after an American academic.
Elbaite – Lithium tourmaline named after the island of Elba.
Liddicoatite – Calcium tourmaline named after an American gemologist.
Tsilaisite – Manganese tourmaline named after a place in Madagascar.
Uvite – Magnesium tourmaline named after a province of Sri Lanka.
Watermelon tourmaline – L Multicoloured tourmaline that exhibits interesting pink, green and white color zones in the same crystal. When crystals are cut in cross section, a pink core with a white band and green edges can be clearly seen, just like a watermelon.
Cat’s eye tourmaline – A rare chatoyant variety of tourmaline. The chatoyancy is usually strongest in green and pink tourmaline.
Image: Google Cultural Institute
The Hamlin Necklace, designed by the discoverer of Maine tourmalines, is set with 70 Maine tourmalines (228.12 total carat weight). It is currently on display at the Mineralogical Museum at Harvard University.
Crown of Empress Anna Ivanovna
The Russian Crown of Empress Anna Ivanovna from 1730 was one of the first ornate crown of its kind for the Russians. The stunning openwork crown is made of silver and adorned with 2536 diamonds, 28 other gemstones and one giant 500 carat red tourmaline.
Fun fact: Many gemstones in the Russian Crown jewels from the 17th Century once thought to be rubies are in fact tourmalines.
Lily Safra Brooch
Image: The Jewellry Editor
A beautiful old-cut pear shape diamond sits in between a twisting vine of green tourmalines. The petals are carved from pinkish red tourmaline. The diamond and tourmaline poppy brooch owned by Lily Safra reached $1,273,320 at Christie’s Auction in 2012.
Paraiba Star of Ocean Jewels
Image: Kaufmann De Suisse
The Kaufmann de Suisse “Paraiba Star of the Ocean Jewels” necklace features the Guinness Book of World Record’s largest cut Tourmaline; a flawless brilliant cut, oval 191.87 carat tourmaline center stone. This spectacular one-of-a-kind necklace is inspired by ocean life.
Which of the October birthstones is your favorite? Do you prefer the mysterious iridescence of opal, or the variety of tourmaline?