December is a unique month in the gemological calendar, distinguished by its association not with a single stone, but with a trio of distinct and captivating blue gemstones: Turquoise, Tanzanite, and Zircon. This abundance offers a remarkable spectrum of color, from the soft, sky-blue of ancient Turquoise to the deep, velvety violet-blue of Tanzanite and the brilliant, clear blue of Zircon. While the traditional and modern lists are dominated by these blue hues, the month also has an alternate stone, the red Ruby, and a specific alternate for December 1st, Bloodstone, providing a surprising contrast to the prevailing cool tones.
This article serves as a comprehensive guide for gemstone enthusiasts, collectors, and those born in the final month of the year. We will explore the history, geology, and unique properties of each of December's official birthstones, delving into the science that defines them and the lore that has made them treasured for millennia. We will also address the specific birthstones associated with December 1st, offering a complete picture for anyone seeking to understand the rich tapestry of gems assigned to this festive month.
The History and Lore of December's Gems
The concept of birthstones is an ancient tradition, with roots in the breastplate of the High Priest of Israel described in the Book of Exodus, which featured twelve stones representing the twelve tribes of Israel. Over time, these stones became associated with the twelve signs of the zodiac and eventually, the months of the year. The December stones, in particular, have a rich and varied history shaped by cultures across the globe.
Turquoise: The Ancient Stone of Protection
Of the three, Turquoise boasts the longest history. It has been cherished for millennia, adorning the pharaohs and other rulers of ancient Egypt. Chinese artisans were carving this gem more than 3,000 years ago. Its name is a testament to its journey into Western culture; "turquoise" derives from the French expression pierre tourques, or "Turkish stone," reflecting its importation into Europe from Turkey during the 13th century. The most prized specimens, known for their "sky blue" or "robin's egg blue" color, historically came from ancient Persia (modern-day Iran). This specific hue is so iconic that it is still commonly referred to as "Persian blue," regardless of its actual origin.
The lore surrounding Turquoise is extensive. It was believed to possess many beneficial powers, such as guaranteeing health and good fortune. A persistent belief from the 13th century onward was that the stone could protect the wearer from falling, particularly from a horse, and that it would shatter upon the approach of disaster as a warning. Hindu mystics believed that seeing a turquoise after beholding the new moon would ensure fantastic wealth. For Native Americans, particularly the Apache, the stone held deep spiritual significance; they believed turquoise could be found by following a rainbow to its end. The Pueblo people of the American Southwest also revered the stone, which is why the United States is now the world's largest provider of turquoise.
Zircon: The Stone of Clarity and Wisdom
Zircon is one of the oldest minerals on Earth, with some specimens dating back billions of years. While it comes in a rainbow of varieties, the blue variety is the one traditionally linked to December. Historically, colorless zircon was a popular diamond simulant due to its high refractive index and brilliant fire. The word "zircon" may derive from the Persian word zargun, meaning "gold-colored," though its most famous hues are blue and colorless. Associated with clarity, wisdom, and a sense of balance, Zircon has long been valued not just for its beauty but for its purported ability to bring peace and prosperity to the wearer.
Tanzanite: The Modern Marvel
In stark contrast to the ancient lineage of Turquoise and Zircon, Tanzanite is a distinctly modern discovery. It was first found in the Merelani Hills of Tanzania in the late 1960s, making it one of the youngest gemstones to enter the global market. Its rapid rise to fame was fueled by its unique color—a rich, velvety violet-blue that shifts depending on the light—and the aggressive marketing of Tiffany & Co., which introduced it to the world in 1968 and named it after its country of origin. Tanzanite is celebrated for representing transformation and new beginnings, making it a popular choice for significant life events and commemorative jewelry.
Geological Formation and Sources
Understanding the origin of these gems reveals why they are so distinct and valued. Each stone forms under unique geological conditions, leading to their individual chemical compositions and physical properties.
Turquoise: A Hydrated Phosphate Mineral
Turquoise is not a silicate mineral like most gemstones; it is a hydrated phosphate of copper and aluminum. Its formation occurs in arid regions where acidic, copper-rich groundwater seeps through aluminum-bearing rocks. Over millions of years, the minerals precipitate, forming veins and nodules of turquoise. The presence of copper is what gives the stone its characteristic blue color, while iron can shift the hue towards green. The United States is currently the world's largest provider of turquoise, with significant deposits in Arizona, Nevada, and New Mexico. Other important sources include Iran (for the classic "Persian blue"), Egypt's Sinai Peninsula, and Afghanistan.
Zircon: An Ancient Silicate Mineral
Zircon is a mineral belonging to the group of nesosilicates. It is the primary source of zirconium and is found in igneous, metamorphic, and sedimentary rocks. Its remarkable durability and resistance to heat and chemical change make it an invaluable tool for geological dating (geochronology). While Zircon is found worldwide, significant commercial deposits are located in Australia, Thailand, Cambodia, and Sri Lanka. The blue color in zircon is typically achieved through heat treatment of brownish zircons, a process that also enhances its brilliance.
Tanzanite: A Unique Variety of Zoisite
Tanzanite is a variety of the mineral zoisite. Its formation is exceptionally rare, believed to have occurred under a unique set of geological circumstances approximately 585 million years ago. The heat and pressure from a massive tectonic event caused the transformation of the host rock, infusing it with the elements necessary to form this gem. This geological event occurred in only one location on the planet: a small, four-square-kilometer mining area in the Merelani Hills of northern Tanzania. This extreme rarity of origin is a key factor in its value and allure. The deep blue to violet-blue color of tanzanite is the result of trace amounts of vanadium within its crystal structure, combined with a careful heat treatment process that is often required to bring out the most desirable hues.
Gemological Properties: A Comparative Analysis
To truly appreciate these gems, one must understand their scientific characteristics. The following table summarizes the key gemological properties of Turquoise, Zircon (blue), and Tanzanite, based on data from authoritative gemological sources.
| Property | Turquoise | Zircon (Blue) | Tanzanite |
|---|---|---|---|
| Chemical Composition | Hydrated copper aluminum phosphate | ZrSiO₄ | Ca₂(Al,Fe)₃(SiO₄)₃(OH) |
| Crystal System | Triclinic | Tetragonal | Orthorhombic |
| Hardness (Mohs Scale) | 5 - 6 | 6.5 - 7.5 | 6.5 - 7 |
| Refractive Index | 1.610 - 1.650 | 1.92 - 2.01 | 1.69 - 1.70 |
| Luster | Waxy to subvitreous | Adamantine to sub-adamantine | Vitreous |
| Durability & Care | Porous, sensitive to chemicals, can be dyed | Good, but can have cleavage planes | Fair, good cleavage, sensitive to heat and shock |
Turquoise: With a hardness of 5 to 6 on the Mohs scale, Turquoise is relatively soft compared to the other December stones. It is often semi-translucent to opaque and can be porous, making it susceptible to damage from chemicals, cosmetics, and even skin oils, which can cause discoloration. High-grade, hard Turquoise from certain localities (like Lander Blue) is an exception and is highly prized. The presence of "matrix"—veins of the host rock—is common and can be a desirable feature, creating intricate patterns.
Zircon: Zircon is significantly harder and more durable, with a hardness of 6.5 to 7.5. Its most notable characteristic is its high refractive index (1.92-2.01), which is higher than that of a diamond (2.42), giving it exceptional brilliance and "fire." However, Zircon has good cleavage in two directions, meaning it can chip or break if struck with sufficient force in the right spot. This makes it less durable than a diamond or sapphire, despite its higher hardness.
Tanzanite: Tanzanite has a hardness of 6.5 to 7, similar to Zircon. However, its most critical property from a durability standpoint is its "trichroism"—the ability to show three different colors (blue, violet, and a reddish-brown or burgundy) when viewed from different crystal directions. This property is so strong that most faceted tanzanites are cut to display the blue-violet hue as the primary color. Tanzanite also has perfect cleavage in one direction, making it susceptible to chipping or breaking if knocked hard. It is also sensitive to sudden temperature changes, which can cause internal fractures.
Symbolism and Metaphysical Beliefs
Beyond their physical beauty, December's birthstones are rich in symbolic meaning and metaphysical lore, which have evolved over centuries and across cultures.
Turquoise: The Master Healer
Turquoise is widely regarded as a stone of protection, wisdom, and tranquility. It is often called the "master healer" in metaphysical circles, believed to align all chakras, stabilize mood, and absorb negative energy. Its association with good fortune and health is ancient and universal. The stone's tendency to change color over time has been interpreted as a sign of its power to connect the wearer to the cycles of nature and life, encouraging an optimistic outlook. For Sagittarians, a December zodiac sign, Turquoise is said to promote rational thinking, helping to temper their tendency to speak before thinking.
Zircon: The Stone of Virtue
Zircon is associated with clarity of thought, wisdom, and spiritual growth. It is believed to help its wearer achieve a state of balance and inner peace. Historically, it was thought to promote honor and purity in its bearer. The colorless variety was used to aid in sleep and bring prosperity, while the blue Zircon of December is linked to communication and self-expression. Its brilliant sparkle is seen as a reflection of an enlightened mind.
Tanzanite: The Stone of Transformation
As a relatively new gem, Tanzanite's metaphysical properties are modern interpretations. It is strongly associated with transformation, representing a bridge between the earthly and spiritual realms. It is believed to stimulate the throat and crown chakras, enhancing intuition, communication, and spiritual awareness. Its unique energy is said to be perfect for those undergoing significant life changes or seeking a higher purpose, making it a powerful stone for meditation and spiritual discovery.
The Special Case of December 1st
While the month as a whole is associated with the blue trio, specific days have alternate stones. For those born on December 1st, the alternate birthstones are Bloodstone and Ruby.
- Bloodstone is a dark green chalcedony (a variety of quartz) characterized by red inclusions of iron oxide, which look like drops of blood. It is a stone of great antiquity, known as the "martyr's stone" and associated with courage, strength, and vitality. Its contrast in color and composition to the primary December stones is striking.
- Ruby, a variety of corundum, is one of the most valuable gemstones in the world. Its vibrant red color is caused by trace amounts of chromium. Historically, it has symbolized passion, love, and power. Its inclusion for December 1st adds a fiery, warm alternative to the cool blues of the month.
Care and Cleaning
Proper care is essential to maintain the beauty and integrity of these gemstones, and their differing properties demand specific attention.
Turquoise: Due to its porosity and lower hardness, Turquoise requires gentle care. It should be cleaned with warm, soapy water and a soft cloth. Avoid ultrasonic cleaners, steam cleaners, and harsh chemicals, including acids and cosmetics, which can permanently damage the stone's surface and color. Store it separately to prevent scratching.
Zircon: While hard, Zircon's cleavage makes it vulnerable to impact. It is best cleaned with warm, soapy water and a soft brush. Avoid ultrasonic cleaners and extreme temperature changes. Due to its high refractive index, it can be mistaken for diamond, but its brittleness requires more careful handling.
Tanzanite: As a gem with perfect cleavage and moderate hardness, Tanzanite is the most fragile of the three. It is highly susceptible to chipping and cracking from impact or sudden temperature changes. It should never be cleaned in an ultrasonic or steam cleaner. The safest method is warm, soapy water and a soft brush. When setting Tanzanite in jewelry, protective settings like bezels are recommended. It is often treated with heat to achieve its desirable blue color; this treatment is stable, but the stone's fragility remains its primary concern.
Conclusion
December's birthstones offer a remarkable journey through geological time, human history, and cultural expression. From the ancient, protective embrace of Turquoise, with its earthy matrix and sky-blue hues, to the brilliant fire and billion-year-old legacy of Zircon, and the modern, transformative allure of Tanzanite, each gem provides a unique narrative. They are united by the color blue, yet distinct in their composition, durability, and lore. For those born in December, the choice between them—or the decision to embrace the fiery red of an alternate like Ruby or Bloodstone—is a personal one, allowing for an expression of individuality that is as deep and multifaceted as the gems themselves. Their enduring appeal lies in this perfect blend of scientific wonder, historical depth, and breathtaking beauty.