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October's Birthstones: Tourmaline and Opal

October's Birthstones: Tourmaline and Opal

Posted by Jessie Tyler on 9th Oct 2020

Birthstones have can have so much meaning to those who wear them. They are also beautiful and full of color. You can make a pendant or ring a more special gift with the addition of a birthstone. And for those born in October, there are actually two birthstones to choose from: tourmaline and opal. Despite their obvious differences—tourmaline’s colors depend on chemical makeup while opal diffracts light to show multiple hues—both are related in their kaleidoscopic range and both have similar rainbow-based legends about their origins on Earth.

Both Tourmaline and Opal make for gorgeous jewelry and can be used to enhance even the most traditional Celtic jewelry designs, like the Claddagh. Both gorgeous gems can make a treasured gift, and accent a ring or pendant, making it a forever treasured piece. There is much symbolism involved when wearing a birthstone in addition to Celtic jewelry. Consider birthstone jewelry with things like the mother’s pendant or a Claddagh ring, and you can give a gift that has mystery and lore. You can check out ShanOre's Birthstone Collection at ShamrockGift.com.

TOURMALINE

The name "tourmaline" literally means "stone of mixed colors" and comes from the Sinhalese words tura mali. And, as its name suggests, you can find every shade of the rainbow within it. A tourmaline is a complex group of minerals that have different chemical compositions and physical properties and magicians of ancient times use tourmaline as a talisman to ward off negative energy and forces of evil. Many people today believe that it wards off negative thoughts, toxins, pollutants, and radiation. Many resulting varieties have their own names from certain elements.

Black tourmaline has a lot of Iron and comes in dark shades. This variety makes up ninety-five percent of all tourmaline, though most of it isn’t gem-quality. Brown tourmaline has a lot of magnesium, which causes colors ranging from brown to yellow. Elbaite has traces of lithium and this is combined with other coloring elements to make a wide variety of options: Red tourmaline (sometimes referred to as pink) is caused by manganese; Blue tourmaline depending on iron and titanium can appear purplish blue or bluish green; Green tourmaline caused by chrome and vanadium can resemble emerald.

Beyond the most common colors for tourmaline, there are several rare forms of the gem. Paraíba tourmaline is the most valuable and recently discovered in Paraiba, Brazil. It is a vividly colored purplish or greenish blue variety. Achroite or colorless tourmaline is extremely hard to find and rare. Parti-colored tourmaline is commonly green and pink and displays more than one color, due to chemical fluctuations during crystallization.

Tourmaline has a hardness of 7 to 7.5 on the Mohs scale, and it is very desirable because of its sheer range of color options. Additionally, through heat called pyroelectricity and through pressure which is piezoelectricity the gem can be charged. When charged, tourmaline can act as a magnet. It does so by oscillating, and by attracting or repelling particles of dust. According to ShanOre jewelry, "the pink tourmaline is believed to instill love, compassion, gentleness and spirituality in those who celebrate October birthdays."

The History of Tourmaline

In a legend of ancient Egyptian times, it is said that tourmaline got its array of colors when it passed through a rainbow on its journey from the center of the Earth. Tourmaline is so colorful that is has often been thought to be other gems throughout history.

A Spanish conquistador found Green Tourmaline in Brazil in the 1500s. He thought it was Emerald. It was not corrected until the 1800s when it was finally identified as Tourmaline by mineralogists.

The name “Schorl” and its variations that are used to describe Black Tourmaline have been used to even before 1400. A village in Saxony, Germany, which is now called Zschorlau was near a mine with black tourmaline deposits and that is where the name originates.

In Sri Lanka, the Dutch East India Company brought Tourmaline to Europe for centuries before traders realized it was Schorl.

The gem’s spike in popularity because of the American tourmaline deposits. In 1876, mineralogist George Kunz started a craze when Tiffany & Co. bought Green Tourmaline from Maine.

In the 1890s, tourmaline was found in California. Native Americans had given certain colors of the gem as funeral gifts for centuries. China represented the biggest market for tourmaline at that point. Dowager Cixi, a Chinese Empress, was very fond of pink tourmaline. She purchased a lot of it from San Diego. The Chinese government collapsed in 1912, and it took Tourmaline trade down with it because the Chinese market was so critical to tourmaline.

In the 1980s and ’90s Brazilian tourmaline discoveries reignited interest in this gem. The material mined in Paraíba displayed gorgeous vivid violets, neon greens, and radiant blues. The world’s largest Tourmaline weighing 191.87 carats was discovered in this region, which has produced the world’s finest, most valuable specimens of tourmaline.

It’s rare to find fine gem-quality tourmaline in bright colors even though plenty of tourmaline is mined around the world. Tourmaline can vary almost as much in cost as it does in color for this reason.

Buying Tips

Tourmaline makes a truly one of a kind gift, as no two tourmaline gems are exactly alike. This makes it the perfect gift as a birthstone for those celebrating an October birthday or an eighth wedding anniversary.

There’s tourmaline to suit a range of styles and budgets, with a large variety source available which provide a lot of different colors and qualities. Like diamonds, tourmaline is evaluated by the criteria color, clarity, cut, and carat weight.

Color

Darker tourmaline that is black is much lower-priced that brightly-colored material. Shades of pink and red are most desirable for the average person.

Green and blue are popular as well, with the most striking coming from Brazil. They are about $10,000 per carat which makes it have the most value out of all Tourmaline.

Clarity

Liquids can get trapped as bubbles during crystallization, so inclusions are common in Tourmaline. In mineralogy, an inclusion is any material that is trapped inside a mineral during its formation. In gemology, an inclusion is a characteristic enclosed within a gemstone, or reaching its surface from the interior. It’s not uncommon for red or pink Tourmaline to display visible inclusions. However, these inclusions can drastically lower the value of other colors.

Rubellite undergoes heat treatment to improve color while another Tourmaline is clarity-enhanced as well to remove inclusions.

Cut

Tourmaline forms in columnar crystals that are slender. Due to this many gems have irregular shaping.

These gems are called “pleochroic,” because they absorb light down the length of a crystal, rather than across it. Pleochroic means that the stone is absorbing different wavelengths of light differently depending on the direction of incidence of the rays or their plane of polarization. This often results in the appearance of different colors according to the direction of view. The cut is critical as they appear in different colors from different directions.

Carat Weight

Paraíba tourmaline is rare in sizes larger than one carat. Because this stone is more popular, it would be more desirable over a large, dark Tourmaline. Color is more valued than size, in this case.

From inexpensive schorl to the highly valued Paraíb, the price of these gems can vary quite a bit. This is due to such a wide range of tourmaline options available.

OPAL

“Opal” means “to see a change in color.” and comes from opallios, a Greek word. Pliny, a Roman scholar, used the word opalus when he wrote that this gem could have the various colors of any precious stone due to its kaleidoscopic features, or “play of color.” This so-called “play-of-color” of Opal’s characteristics was explained in the 1960s. Opal is composed of spheres of silica that was microscopic. It makes the light catch the stone, displaying the many colors of the rainbow. Common Opals have no play of color. However, the much more flashy gems which are referred to as Precious Opals, do. The Boulder Opal and Fire Opal and are the only ones universally recognized, but there are many types of Opal. Opals have a body color of white or black and this is how people often refer to them.

Australia is Opal’s classic country of origin. When the rains brought deposits of silica into cracks underground between the rock layers they formed Opal once the water dissipated. On occasion, silica got into spaces in between wood, skeletons, and seashells resulting fossils that were opalized. During the mid-1800s, Opal was discovered in Australia. Since then, this country has produced nearly 100 percent of the world’s Opals. It is also mined in the United States in Nevada and Idaho, as well as Mexico, Honduras, Ethiopia, Brazil, and the Czech Republic.

Opal is about twenty percent water. This, along with only a 6 on the Mohs scale, Opal is very delicate. It can crack, also called a “craze,” when dehydrated, under harsh temperatures, or direct light exposure. Opal has been thought to bring luck for hundreds of years. This makes wearing Opal well worth the extra care. Some may say there is bad luck associated with wearing Opal when it is not their birthstone. However, Opal remains popular with everyone, not just those born in October.

The History of Opal

Opals fell from bolts of lightning out of the sky according to Arabic legend. The Aborigines of Australia thought Opal came to Earth via rainbow with the creator. As his feet touched the land, the creator left these colorful and beautiful stones.

Pliny, a Roman scholar, compared opals to volcanoes and vibrant paintings, in 75 AD, noting they could simulate shades of any gems with their dancing play of color.

Opal was thought to have the powers of any stone it resembled. This made the stone very lucky to possess in the Middle Ages. The 1829 book, “Anne of Geierstein,” by Walter Scott, changed Opal’s legend of being lucky. The book was about a princess of enchantment. Her opal that she wore changed colors with her moods. Some holy water destroyed the stone’s magic and the woman died shortly thereafter. Within a year after the book was published, Europe Opal sales were down fifty percent. Opals were thought to be bad luck.

The discovery in Australia in 1850 revived the gem’s image. Mining in the Australian outback began. They were producing many of the world's finest opals as well as nearly 100 percent of the world’s supply. In 2005, Olympic Australis, the world’s largest and most valuable Opal, was valued at $2.5 million dollars. It was found in Coober Pedy, Australia in 1956. It was named Olympic Australis because it was discovered during the Olympic Games in Melbourne, Australia. It is almost a foot long and it is 17,000 carats which weigh an astonishing 7.6 pounds. In the 1960s, scientists discovered the round silica structure of the Opal and, after that, they soon after figured out how to synthesize it in the mid-1970s.

There have been recent discoveries of Opal in Ethiopia which made it even more popular. The deposits in the Wollo, a Province, were discovered in the late 2000s. This brought many more vivid Opals to the global market. Supplies of classic opal in Australia are depleting and have impacted the price of this unique gem. Since Opal is loved by many for its play-of-color, there is still a high demand for the stone.

Buying Tips

Some have stated that opal is bad luck for those born outside of the month of October, but Opal has been a good luck charm for centuries. It is also a gift to give on fourteenth wedding anniversaries, however, and Opal’s kaleidoscopic play-of-color can suit many changing tastes and moods. Opals can be evaluated by carat weight, cut, color, and clarity, and there are additional conditions to grade them by.

Color

Key factors when grading Opals are the so-called “body color” in the background as well as the “play-of-color.”. Milky white varieties are less valued than dark backgrounds because dark provides more contrast against vivid play-of-color. From faint to brilliant, Play-of-color is measured on a brightness scale of one to five. Orange and red and are warm colors and more rare and valued. Greens and blues are common but both coverage and range also play a part.

Pattern

Descriptive titles like stained Chinese Writing, Peacock, Glass, and Rolling Fire are names for a pattern of Opal. This is unique to grade the opal. Concentrated and large patches are preferred while small specks are less favored.

Clarity

Transparent crystal opals are favored. Opacity makes black opals increase in value. Instability is indicated by a milky, cloudy haze and it lowers value. This means that different opal varieties have varying clarity standards.

Under direct light, extreme temperatures, or dehydration Opal can easily crack or “craze.” Cracked Opal has much less value, as would be expected. It can also fracture. Opal always requires delicate care regardless of value.

Cut

Fine opals are often cut into irregular shapes because this an manipulate color. If it is possible, any opal should be made into rounded domes. There are layers that are then mounted onto a dark stone like Obsidian or Onyx. This is called a doublet. It might be capped with plastic or clear glass. This is called a triplet. This makes the somewhat fragile gem easier to wear.

To enhance their luster, Opals may be treated with wax, oil, smoke, or plastic. Identifying enhancements or synthetic materials may require specialized lab equipment.

If you liked the jewelry you saw here or enjoyed learning about the meanings and history of October's birthstones, don’t forget to visit ShamrockGift’s Birthstone Collection for a personalized gift idea.

Originally Published on Sep 28, 2018