October, the tenth month of the year, is celebrated with two distinct and captivating gemstones: opal and tourmaline. While the tradition of assigning gemstones to each month of the year has evolved over time, October remains one of the few months with multiple birthstones. This unique duality reflects both the historical significance of these stones and their diverse beauty. Opal, with its shifting play-of-color, and tourmaline, particularly in its pink hue, offer a stunning array of colors and symbolic meanings. This article delves into the geological formation, historical lore, gemological properties, and cultural symbolism of these two October birthstones, supported by detailed information from the provided sources.
Introduction
October is a month marked by transformation—autumn leaves fall, temperatures cool, and the days grow shorter. Yet, within the world of gemology, October is equally marked by transformation and variety. The two birthstones assigned to this month, opal and tourmaline, each carry their own rich histories and distinct characteristics. Opal, the traditional October birthstone, is renowned for its iridescent play-of-color, while tourmaline, especially pink tourmaline, serves as the modern alternative. The choice of two stones for October reflects the evolving nature of birthstone traditions and the desire to accommodate both historical significance and modern accessibility.
This article explores the geological origins, properties, historical uses, and cultural symbolism of both opal and tourmaline. It also addresses the reasons behind October’s dual birthstone status and provides practical advice on care and selection for those interested in owning these gems.
History and Lore
Opal: A Stone of Transformation and Mystery
The name "opal" is believed to have originated in India, where the Sanskrit word upala meant "precious stone." The Romans later adopted the term opalus, which eventually evolved into the English word "opal." Opal has long been regarded as a stone of transformation and mystery. Ancient Greeks believed opals granted the power of prophecy and protection from disease. In Rome, opals were considered symbols of hope and purity. The Bedouins, who lived in arid regions where opals were found, believed the stone contained lightning and fell from the sky during thunderstorms.
Opal was also associated with the 14th wedding anniversary, symbolizing enduring love and commitment. During the Victorian era, opal became especially popular in England, where it was seen as a symbol of love and innocence. However, this popularity was short-lived due to a superstition that opals were "evil" and could bring bad luck, especially to those who did not find them naturally. This belief was famously perpetuated by the English writer Sir Walter Scott in his novel Anne of Geierstein, where an opal is described as a cursed stone.
Despite such superstitions, opal has been cherished throughout history for its unique beauty. The stone’s iridescent colors have inspired poets and artists, who have likened its appearance to fireworks, galaxies, and volcanoes.
Tourmaline: A Stone of Color and Compassion
Tourmaline is a relatively modern addition to the list of October birthstones. In 1912, the National Association of Jewelers replaced opal with pink tourmaline as the October birthstone. This shift was likely influenced by the growing popularity of tourmaline in jewelry and its availability compared to opal, which can be more delicate and difficult to work with.
Tourmaline has a long and colorful history. The name "tourmaline" comes from the Sinhalese word turmali, meaning "mixed stones." This name reflects the gemstone’s wide variety of colors, which range from black and green to blue, pink, and even combinations of multiple hues in a single crystal. The Egyptians believed tourmaline took on so many colors because it traveled down a rainbow from the sun to Earth.
One of the most notable figures in tourmaline history is Empress Dowager Tzu-Hsi of China. In the late 1800s, she developed a deep passion for pink tourmaline and purchased nearly the entire production from a California mine. Her love for the gemstone was so profound that she was even laid to rest on a pink tourmaline pillow, with her extensive collection of tourmaline transformed into exquisite carvings.
Tourmaline, particularly in its pink form, is associated with the heart and symbolizes compassion, love, and balance. It is often used in jewelry to promote emotional healing and to enhance feelings of friendship and self-love.
Geological Formation and Sources
Opal: A Unique and Delicate Stone
Opal is a unique gemstone in that it is not a mineral in the traditional sense. It consists of microscopic silica spheres arranged in a lattice-like structure. These spheres are so small that light is refracted and diffracted between them, creating the famous "play-of-color" effect. Opals are typically formed in near-surface volcanic rocks, particularly in cavities and cracks. They can also form in sedimentary volcanic ash rock, where percolating water dissolves silica and eventually deposits it in the form of opal.
Opal is most commonly found in Australia, which is the world's largest producer of precious opal. Other notable sources include Ethiopia, Mexico, Brazil, and Honduras. Ethiopian opal, in particular, has gained popularity in recent years due to its vibrant colors and affordability compared to Australian opals.
Despite its beauty, opal is relatively soft and fragile, with a hardness of 5 to 6.5 on the Mohs scale. It is also prone to fractures and dehydration, which can cause it to crack or lose its luster if not properly cared for. Opal is not a true mineral in the traditional sense because it lacks a crystalline structure and is composed primarily of water.
Tourmaline: A Diverse and Durable Stone
Tourmaline is a complex borosilicate mineral that comes in a wide variety of colors due to its chemical composition. The most common type of tourmaline found in jewelry is elbaite, a variety that can contain elements such as manganese, iron, aluminum, and potassium, which influence its color. The pink hue of tourmaline is primarily due to the presence of manganese.
Tourmaline is formed in pegmatite and granite rocks, often in hydrothermal environments where hot, mineral-rich fluids move through cracks and cavities. The conditions required for tourmaline formation are relatively unique, which is why it is not found in as many locations as other gemstones.
The most significant sources of tourmaline include Brazil, Nigeria, Sri Lanka, Zambia, China, and the United States, particularly California and Nevada. Brazil is especially known for producing high-quality tourmaline in a wide range of colors.
Compared to opal, tourmaline is much more durable, with a hardness of 7 to 7.5 on the Mohs scale. This makes it more suitable for everyday wear in jewelry. However, like all gemstones, tourmaline can still be damaged by excessive heat, chemicals, or sudden temperature changes.
Gemological Properties
Opal: A Stone of Shifting Hues
Opal is one of the few gemstones that does not have a consistent color. Instead, it is known for its play-of-color, a phenomenon where it displays a range of colors that shift depending on the angle of light. This effect is due to the microscopic silica spheres within the stone, which are arranged in a lattice that causes light to refract and diffract. The most valuable and sought-after opals are those with bold, vivid play-of-color across the entire surface.
The chemical composition of opal is primarily hydrated silica (SiO₂·nH₂O), and it contains a significant amount of water—up to 10% in some cases. This high water content is one of the reasons why opal is more fragile and requires special care.
Opal is not a true mineral in the traditional sense because it lacks a defined crystalline structure. Instead, it is classified as a amorphous mineraloid, meaning it is a solid substance that does not have a regular internal structure like most minerals.
The clarity of opal is not typically described in the same way as diamonds or other transparent gemstones. Instead, the value of opal is determined by the intensity and variety of its play-of-color, the background color, and the pattern in which the colors appear.
Opal is used in a wide variety of jewelry, including rings, pendants, and earrings. However, due to its fragility, it is not always recommended for use in rings that are worn daily, unless the stone is properly protected.
Tourmaline: A Stone of Vibrant Color
Tourmaline is a borosilicate mineral with a hexagonal crystal structure, which is why it often forms in long, prism-like crystals. The most common type of tourmaline found in jewelry is elbaite, which can appear in a wide range of colors depending on the trace elements present in the stone.
The chemical formula of tourmaline is complex and can vary depending on the specific type. For example, pink tourmaline is typically composed of sodium, lithium, aluminum, and manganese, while black tourmaline (commonly known as schorl) contains iron.
Tourmaline is known for its high hardness, with a rating of 7 to 7.5 on the Mohs scale, making it relatively durable and suitable for use in rings, bracelets, and necklaces. It is also resistant to heat and chemicals, which makes it relatively easy to work with in jewelry settings.
The color of tourmaline is one of its most defining characteristics. While pink tourmaline is the most well-known October birthstone, tourmaline can also be found in green, blue, red, yellow, and even color-changing varieties. Some tourmaline crystals contain multiple colors, a phenomenon known as watermelon tourmaline, which has a pink center and green outer layers.
Tourmaline is also known for its electrostatic properties. It is one of the few gemstones that can generate an electric charge when heated or subjected to pressure, a property known as pyroelectricity. This is why tourmaline is sometimes used in scientific and electronic applications.
Symbolism and Metaphysical Beliefs
Opal: A Stone of Hope, Purity, and Transformation
Throughout history, opal has been associated with hope, purity, and transformation. In ancient Greece, it was believed to grant the power of prophecy and protection from disease. In Europe, it was seen as a symbol of truth and innocence, and it was often given as a gift to express deep affection and commitment.
Opal has also been linked to love and emotional healing. It is said to enhance emotional stability and promote a sense of inner peace. Some believe that opal helps individuals embrace change and adapt to new situations, making it a powerful stone for those undergoing personal or emotional transformation.
Due to its play-of-color, opal is also associated with divine inspiration and creativity. It is believed to enhance artistic expression and encourage individuals to explore their inner world. In some cultures, opal is also considered a stone of good luck, particularly when found naturally in the earth.
Tourmaline: A Stone of Emotional Balance and Protection
Tourmaline, especially in its pink form, is associated with love, compassion, and emotional balance. It is believed to promote self-love and forgiveness, helping individuals overcome emotional pain and develop a deeper sense of empathy and understanding. Pink tourmaline is often used in jewelry to enhance feelings of friendship and harmony, making it an ideal gift for loved ones.
Tourmaline is also known as a stone of protection, particularly in its black form (schorl). It is believed to absorb negative energy and provide a shield against harmful influences. Some cultures use tourmaline to purify the body and mind, promoting inner strength and resilience.
Due to its wide range of colors, tourmaline is also associated with diversity and inclusivity. It is seen as a symbol of the beauty of individuality and the importance of embracing differences. In some metaphysical traditions, tourmaline is used in energy healing to clear the chakras and restore balance to the body's energy system.
Care and Cleaning
Opal: A Delicate Gemstone
Due to its high water content and fragile structure, opal requires special care to maintain its beauty and durability. It should be stored in a cool, dry place to prevent dehydration, which can cause it to crack or lose its luster. Opal should also be kept away from direct sunlight and extreme temperature changes, as these can cause it to become brittle.
When cleaning opal, it is best to use a soft, damp cloth to gently wipe the surface. Ultrasonic cleaners and steam cleaners should be avoided, as they can cause the stone to lose its water content and become damaged. Opal should also be kept away from harsh chemicals, perfumes, and cosmetics, which can dull its appearance.
Because opal is not suitable for daily wear, it is important to consider the type of jewelry in which it is set. Opal is best suited for pendants, earrings, and brooches, where it is less likely to be subjected to impact or abrasion. If worn in a ring, it should be set in a protected setting to prevent damage.
Tourmaline: A Durable and Easy-to-Care Gemstone
Tourmaline is much more durable than opal, with a hardness of 7 to 7.5 on the Mohs scale. This makes it suitable for everyday wear in rings, bracelets, and necklaces. However, like all gemstones, tourmaline can still be damaged by excessive heat, chemicals, and sudden temperature changes.
When cleaning tourmaline, it is best to use a mild soap and warm water with a soft cloth or brush. Ultrasonic and steam cleaners are generally safe to use, but it is best to check with a professional jeweler if you are unsure.
Tourmaline should be stored in a cool, dry place away from direct sunlight. It can be stored with other gemstones, as it does not react with other materials. However, it is best to avoid exposure to harsh chemicals, as these can potentially dull the stone's luster.
Because tourmaline is resistant to heat and chemicals, it is relatively easy to maintain and can be worn in a wide variety of jewelry settings. It is an excellent choice for everyday wear and is particularly well-suited for rings and earrings.
Conclusion
October is a month of change and transformation, and its two birthstones—opal and tourmaline—reflect this theme in both their beauty and symbolism. Opal, with its iridescent play-of-color, is a stone of mystery, hope, and emotional transformation, while tourmaline, especially in its pink form, is a stone of love, compassion, and emotional balance.
The duality of October’s birthstones highlights the evolving nature of gemstone traditions, as well as the diversity of gemstone properties and symbolism. Opal, the traditional October birthstone, is a unique and delicate gemstone that requires special care, while tourmaline, the modern alternative, is durable and versatile, making it ideal for everyday wear.
For those born in October, these gemstones offer a beautiful way to celebrate their birth month, whether through jewelry, collections, or spiritual practices. Whether you choose the shifting hues of opal or the vibrant colors of tourmaline, these October birthstones are sure to bring beauty, meaning, and joy to those who wear them.