October Birthstone - Opal & Tourmaline
The mesmerizing gemstones with a kaleidoscope of colors symbolizing hope and creativity
About October's Birthstones
October is one of the few months with two birthstones: the traditional opal and the modern tourmaline. Opal is known for its kaleidoscopic play of colors, while tourmaline is celebrated for occurring in more colors and color combinations than any other gemstone.
Opals are truly unique in the gemstone world. Their internal structure diffracts light, creating a mesmerizing play of colors that seems to dance across the stone's surface. No two opals are exactly alike, making each one a one-of-a-kind treasure. The name "opal" is thought to derive from the Sanskrit word "upala," meaning "precious stone," and later the Greek "opallios," meaning "to see a change of color."
Tourmaline, October's second birthstone, is equally fascinating. Its name comes from the Sinhalese word "turmali," meaning "mixed colored stones," reflecting tourmaline's incredible color diversity. From watermelon tourmaline with its pink and green zones to the electric blue Paraíba variety, tourmaline offers a rainbow of options for those born in October.
Opal & Tourmaline Properties
Physical Properties
- Mineral: Opal: Hydrated silica / Tourmaline: Complex borosilicate
- Color: Opal: Multicolored with play-of-color / Tourmaline: Virtually all colors
- Hardness: Opal: 5.5-6.5 / Tourmaline: 7-7.5 on Mohs scale
- Transparency: Both range from transparent to opaque
- Refractive Index: Opal: 1.44-1.46 / Tourmaline: 1.624-1.644
- Crystal System: Opal: Amorphous / Tourmaline: Trigonal
Symbolic Meaning
- Hope: Both stones are believed to inspire optimism
- Creativity: Associated with artistic inspiration and imagination
- Inspiration: Thought to enhance creative thinking
- Innocence: Particularly associated with opal
- Healing: Believed to have therapeutic properties
- Protection: Historically worn as protective talismans
Sources & Origins
- Opal Major Sources: Australia, Ethiopia, Mexico
- Opal Other Sources: Brazil, United States
- Tourmaline Major Sources: Brazil, Afghanistan, United States
- Tourmaline Other Sources: Madagascar, Mozambique, Nigeria, Pakistan
- Historical Source: Australian opals have been mined since the 1800s
- Modern Source: Ethiopian opals discovered in the 2000s
Care & Maintenance
- Opal: Clean with mild soap and lukewarm water using a soft cloth
- Opal: Avoid ultrasonic cleaners, steam cleaners, and harsh chemicals
- Opal: Protect from sudden temperature changes and prolonged heat
- Opal: Store wrapped in soft cloth, separate from other jewelry
- Opal: Avoid dehydration by occasionally wiping with a damp cloth if stored long-term
- Tourmaline: Clean with mild soap and warm water using a soft brush
- Tourmaline: Ultrasonic cleaners generally safe for untreated stones
- Tourmaline: Avoid prolonged exposure to strong heat which can alter color
- Tourmaline: Store separately to prevent scratching softer gemstones
The Rich History of October's Birthstones
Opals have been treasured for thousands of years, with the earliest known opal artifacts dating back to around 4000 BCE in Kenya. The ancient Romans prized opals above all other gemstones, calling them "opalus," meaning "precious stone." They believed opals contained the powers of all gemstones whose colors were represented in the opal's play of color.
In medieval times, opals were believed to bring good fortune as they possessed all the virtues of each gemstone's color. However, in the 19th century, opals gained an undeserved reputation for bad luck, largely due to Sir Walter Scott's novel "Anne of Geierstein" (1829), where an opal talisman brought misfortune to its owner. This superstition damaged the opal market for decades.
Tourmaline has a shorter documented history, with significant discoveries occurring only in the 16th century when Portuguese explorers found green tourmalines in Brazil, initially mistaking them for emeralds. The name "tourmaline" comes from the Sinhalese word "turmali," meaning "mixed colored stones."
In the late 1800s, tourmaline became especially popular thanks to Tiffany & Co. gemologist George Kunz, who wrote extensively about the gem and its varieties. In the early 1900s, tourmaline gained further popularity when the Dowager Empress Cixi of China developed a passion for pink tourmaline, purchasing large quantities from mines in California.
Opal & Tourmaline Varieties
Both opal and tourmaline come in a stunning array of varieties, each with its own unique characteristics:
White/Milky Opal
The most common variety, white or milky opal has a white or light body color with flashes of spectral colors. Australian white opals are the most well-known examples of this variety.
Black Opal
The most valuable type of opal, black opal has a dark body color (black, dark blue, dark green) that makes the play of color stand out dramatically. The finest examples come from Lightning Ridge, Australia.
Fire Opal
Known for its transparent to translucent body with vibrant yellow, orange, or red background color. Mexican fire opals are the most famous, though they often lack the play of color seen in other opals.
Boulder Opal
Found in Queensland, Australia, boulder opal forms in ironstone boulders as thin seams. The finished gems often include some of the host rock as a natural backing, creating a dramatic contrast with the opal's play of color.
Crystal Opal
Transparent to semi-transparent with a clear background that allows light to pass through, enhancing the brilliance of the play of color. These can have any body color but are distinguished by their transparency.
Watermelon Tourmaline
A striking variety that displays green on the outside and pink/red on the inside, resembling a watermelon slice when cut perpendicular to the crystal's length. This natural color zoning makes it highly prized by collectors.
Paraíba Tourmaline
An extremely rare and valuable variety first discovered in Brazil's Paraíba state in the 1980s. Known for its vivid neon blue to green colors caused by copper content, these tourmalines command the highest prices per carat.
Rubellite
The red to pink variety of tourmaline, rubellite maintains its color in all lighting conditions, unlike some pink tourmalines that can appear grayish in certain lights. Fine rubellites can resemble rubies.
Indicolite
The blue variety of tourmaline, ranging from light to dark blue, sometimes with a slight greenish tint. Fine specimens with pure blue color are highly valued.
Chrome Tourmaline
A vivid green variety colored by chromium, the same element that gives emeralds their color. These tourmalines can resemble fine emeralds and are primarily found in East Africa.
Fascinating Facts About October's Birthstones
Fact #1
Opals contain up to 20% water trapped within their silica structure, making them sensitive to extreme dryness. Ancient opals that have been stored in very dry conditions for extended periods can develop crazing (a network of tiny cracks) if exposed to moisture too quickly.
Fact #2
Australia produces approximately 95% of the world's precious opals, with fields in Lightning Ridge, Coober Pedy, and Andamooka being the most famous sources. However, in recent years, Ethiopia has emerged as an important new source of high-quality opals.
Fact #3
The play of color in opals is not caused by pigments or dyes but by the diffraction of light through a regular pattern of microscopic silica spheres within the stone. The size of these spheres determines which colors are reflected.
Fact #4
Tourmaline is pyroelectric, meaning it can generate an electrical charge when heated or cooled. When charged, tourmaline can attract dust particles, which led Dutch jewelers in the 1700s to use the gem to pull ash from their meerschaum pipes, calling it the "aschentrekker" or "ash puller."
Fact #5
Tourmaline is also piezoelectric, generating an electrical charge when pressure is applied. This property makes it useful in various industrial applications, including pressure gauges and depth sounding equipment.
Fact #6
The Paraíba tourmaline, discovered in the late 1980s in Brazil, created a sensation in the gem world with its electric blue-green color. These tourmalines can sell for over $30,000 per carat, making them among the most expensive colored gemstones in the world.
Opal & Tourmaline in Jewelry
Both opal and tourmaline offer unique characteristics that make them popular choices for various types of jewelry. Here are some popular ways these October birthstones are used in jewelry:
Opal Jewelry
- Protective Settings: Due to opal's relative softness, it's often set in protective bezels or as inlays rather than in prong settings that might put pressure on the stone.
- Doublets & Triplets: To protect thin opal or enhance color play, opals are sometimes made into doublets (opal + backing) or triplets (backing + opal + clear cap) for jewelry use.
- Vintage Styles: Opals were extremely popular during the Art Nouveau and Art Deco periods, and vintage-inspired opal jewelry remains popular today.
- Statement Pieces: Large boulder opals often become the centerpiece of statement pendants or brooches that showcase their unique patterns.
Tourmaline Jewelry
- Color Variety: Jewelry designers often create collections featuring tourmalines in various colors, highlighting the stone's diversity.
- Watermelon Slices: Watermelon tourmaline is often cut to display its distinctive pink and green color zones, creating unique pendants and earrings.
- Mixed Gemstone Designs: Tourmaline pairs beautifully with other gemstones, creating colorful, multi-stone designs.
- Faceted & Cabochon Cuts: Tourmaline's versatility allows it to be cut in various ways, from traditional facets to smooth cabochons that highlight phenomena like cat's eyes.
Styling Tips
- Opals pair beautifully with both yellow gold, which enhances their warm tones, and white metals, which create a modern contrast.
- For a complementary color scheme, pair blue-green tourmalines with peach or pink stones, or pink tourmalines with green accents.
- October birthstone jewelry looks particularly striking against neutral-colored clothing, allowing the colorful stones to be the focal point.
- Consider your lifestyle when choosing between opal and tourmaline—tourmaline's greater durability makes it better suited for everyday wear, while opals may be better reserved for special occasions.
Explore Other Birthstones
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