The December Birthstone: Turquoise, Tanzanite, and Blue Topaz in Gold Jewelry

December, the final month of the year, is marked by the presence of three distinct birthstones: Turquoise, Tanzanite, and Blue Topaz. Each of these gemstones carries its own set of historical, cultural, and gemological significance. When set in gold, whether 14k, 18k, or vermeil, these stones are not only elevated in their beauty but also become heirloom-worthy pieces of jewelry. This article explores the properties, symbolism, and craftsmanship behind December birthstone gold necklaces, with a particular focus on the gemstones and their relevance in both modern and historical contexts.

A Historical and Cultural Overview of December Birthstones

The tradition of birthstones is ancient, with roots in biblical and cultural references. December’s selection of stones—Turquoise, Tanzanite, and Blue Topaz—has evolved over time, incorporating both historical lore and contemporary appreciation. Each of these gemstones was adopted as a December birthstone for its unique properties and symbolic meaning.

Turquoise: A Stone of Protection and Communication

Turquoise is one of the oldest known gemstones, with a history that stretches back thousands of years. Its vibrant blue-green hues have been revered by ancient civilizations across the globe, including the Egyptians, Persians, and Native Americans. In Egypt, turquoise was used in jewelry and amulets as a symbol of life and protection. It was also associated with the goddess Iset, who was linked to fertility and motherhood.

In Native American cultures, particularly among the Navajo and Zuni, turquoise is considered a sacred stone. It is believed to promote healing, balance, and spiritual connection. The stone was often used in ceremonial jewelry, such as pendants and inlay work, and was thought to bring good fortune and protection.

In modern times, turquoise is still valued for its calming properties. According to the sources, it is said to promote serenity and self-expression, making it an ideal stone for those seeking confidence and creativity. It is also associated with wisdom and good fortune, which aligns with its popularity as a December birthstone.

Tanzanite: A Modern Discovery with Ancient Aesthetics

Tanzanite, on the other hand, is a relatively new addition to the birthstone tradition. Discovered in Tanzania in the 1960s, it was officially designated as a birthstone in 1982. The gemstone is known for its vibrant blue to violet colors, which are caused by the presence of vanadium and the way the stone is cut and treated.

Tanzanite is unique in that it is only found in one location on Earth, the Merelani Hills in Tanzania. This rarity makes it a highly valuable and sought-after gemstone. Its deep, saturated colors have made it a favorite in vintage and modern jewelry designs, especially in gold settings, which complement its regal tones.

Culturally, tanzanite is often associated with transformation and emotional healing. It is believed to help individuals overcome emotional blocks and promote clarity of thought. These symbolic meanings, along with its natural beauty and exclusivity, have contributed to its adoption as a December birthstone.

Blue Topaz: A Stone of Clarity and Insight

Blue Topaz, the third December birthstone, is a more affordable and versatile option compared to the other two. It is known for its clear, pale blue to deep blue hues, depending on how it is irradiated or heat-treated. Blue topaz is a silicate mineral and is often found in Brazil, the United States, and Mexico.

Historically, blue topaz has been associated with healing and protection, particularly in European and Asian cultures. It is also believed to enhance intuition and communication, making it a popular choice for those seeking emotional clarity and insight.

In jewelry design, blue topaz is highly versatile. It can be found in pear-shaped, round, emerald-cut, and other forms, and it works well in both gold and silver settings. Its brilliance and affordability make it a popular alternative to more expensive blue gemstones, such as sapphires or tanzanite.

Geological Formation and Sources of December Birthstones

Understanding the geological origins of these gemstones is key to appreciating their beauty and value. Each of the December birthstones forms under specific conditions, and their natural sources vary in availability and quality.

Turquoise: A Sedimentary Marvel

Turquoise is a phosphate mineral formed through hydrothermal alteration of copper deposits. It is typically found in copper-rich, arid regions, where it is deposited in veins and nodules within limestone or sandstone. The formation process involves chemical reactions between copper, aluminum, and phosphorus, along with the presence of water and organic material.

The most famous sources of turquoise include:

Persia (Iran) – Known for producing some of the richest and most intensely colored turquoise in history.
Egypt – Ancient Egyptian turquoise was sourced from the Sinai Peninsula.
United States – Particularly New Mexico, Nevada, and Arizona, where turquoise has been mined for centuries by Native American artisans.

Modern turquoise used in jewelry is often ethically sourced and may be treated with dyes or resins to enhance its color and durability.

Tanzanite: A Unique Geologic Phenomenon

Tanzanite is a trigonal mineral composed of calcium aluminum silicate with vanadium impurities, which gives it its blue to violet color. It is only found in the Merelani Hills of Tanzania, where it forms under specific high-pressure, low-temperature conditions.

The rarity of tanzanite is due to the limited geographic distribution of its formation. The geological conditions that allow tanzanite to develop are extremely rare, and as a result, the supply of high-quality tanzanite is limited.

Tanzanite is often heat-treated to enhance its color, turning it from a brownish purple to a rich blue-violet. This treatment is common and stable, making it a popular and affordable luxury gemstone.

Blue Topaz: A Silicate with a Variety of Hues

Blue topaz is a silicate mineral composed of aluminum and fluorine. It is one of the hardest gemstones, with a Mohs hardness of 6 to 6.5, making it relatively durable and suitable for daily wear in jewelry.

Natural blue topaz is rare, and most blue topaz in the market is treated with **irradiation and heat to produce the deep blue color. The treatment is stable and permanent, and the gemstone remains chemically and structurally unchanged.

Blue topaz is mined in various parts of the world, including:

Brazil – The largest source of topaz in general.
United States – Particularly in Colorado and Texas.
Mexico – Known for producing some of the finest blue topaz.

These sources ensure a steady supply of blue topaz, which is easily accessible and affordable, making it a popular choice for gold jewelry.

Gemological Properties of December Birthstones

The scientific properties of these gemstones—such as hardness, refractive index, color, and clarity—play a crucial role in their suitability for jewelry and their overall value.

Turquoise: A Soft, Porous Stone

Turquoise has a Mohs hardness of 5 to 6, making it relatively soft compared to other gemstones. It is also porous and susceptible to damage from acids, oils, and extreme temperatures.

Key properties of turquoise include:

Chemical formula: CuAl₆(PO₄)₄(OH)₈·4H₂O
Hardness: 5–6 on the Mohs scale
Refractive index: 1.60–1.65
Luster: Waxy to sub-vitreous
Color: Blue to green, depending on the presence of copper and iron
Clarity: Often opaque with visible matrix patterns

Because of its softness and porosity, turquoise requires special care when worn and stored. It is best avoided in high-impact settings and should be stored separately from other jewelry to prevent scratching.

Tanzanite: A Deep and Radiant Stone

Tanzanite has a Mohs hardness of 6 to 6.5, making it more durable than turquoise but still not suitable for everyday wear in high-impact settings.

Key properties of tanzanite include:

Chemical formula: CaAl₆(PO₄)₃(SO₄,F,OH)·5H₂O
Hardness: 6–6.5 on the Mohs scale
Refractive index: 1.694–1.704
Luster: Vitreous
Color: Blue to violet, with pleochroism (displaying different colors when viewed from different angles)
Clarity: Often included, with visible inclusions that add character

Tanzanite is known for its pleochroism, a property that allows it to display different colors depending on the angle of light. This makes it a visually striking gemstone, especially when cut and polished with precision.

Blue Topaz: A Durable and Radiant Stone

Blue topaz has a Mohs hardness of 6 to 6.5, similar to tanzanite, and is more durable than turquoise. It is less prone to damage and is suitable for daily wear in jewelry.

Key properties of blue topaz include:

Chemical formula: Al₂SiO₄(F,OH)₂
Hardness: 6–6.5 on the Mohs scale
Refractive index: 1.61–1.63
Luster: Vitreous
Color: Blue (due to irradiation and heat treatment)
Clarity: Often eye-clean or with minor inclusions

Blue topaz is a silicate mineral that is easily treated to enhance its color. The blue color is not natural in most cases, but the treatment is stable and widely accepted in the gemstone industry.

December Birthstone Gold Necklaces: Craftsmanship and Design

December birthstone gold necklaces are a celebration of both gemstone beauty and metalwork artistry. Whether in 14k gold, 18k gold, or vermeil, these necklaces are designed to highlight the natural or treated colors of the stones while ensuring durability and elegance.

18k Gold: A Timeless and Durable Setting

18k gold is a popular choice for high-quality jewelry, particularly for birthstone pendants and necklaces. It is 75% pure gold and 25% other metals, such as copper, silver, or zinc, which increase its hardness and longevity.

18k gold is ideal for setting turquoise, tanzanite, and blue topaz, as it complements their colors and provides a secure setting. It is also less prone to tarnishing than silver or lower karat gold.

Examples of 18k gold December birthstone necklaces include:

Turquoise pendants with yellow or rose gold settings
Tanzanite stones set in white or yellow gold
Blue topaz in pear-shaped or emerald-cut settings

These designs often feature adjustable chains, lobster clasps, and handcrafted metalwork, making them both functional and aesthetically pleasing.

14k Gold: A Balance of Affordability and Strength

14k gold is more affordable than 18k gold while still offering good durability and resistance to wear. It is 58.3% pure gold and is often used in everyday jewelry, including birthstone necklaces.

14k gold is particularly well-suited for tanzanite and blue topaz, as its warm or cool tones can enhance the stones’ colors. It is also commonly used in vermeil, where it is layered over sterling silver for added luster and strength.

Some 14k gold December birthstone necklaces feature:

Multiple gemstones, such as tanzanite paired with diamonds
Customizable engravings or photo inserts
Vintage or modern designs with hidden hinges and secure closures

These necklaces are often handcrafted, allowing for personalization and attention to detail.

Vermeil and Solid Gold: Luxury and Longevity

Gold vermeil is a high-quality finish in which 18k gold is layered over sterling silver to a minimum thickness of 2.5 microns. This technique provides a luxurious appearance while being more affordable than solid gold.

Solid gold December birthstone necklaces, on the other hand, are 100% gold and are rarely alloyed with other metals. These pieces are highly durable and develop a unique patina over time, making them ideal for heirloom jewelry.

Both vermeil and solid gold are popular choices for December birthstone necklaces, particularly those featuring tanzanite or blue topaz, which require a strong and elegant setting.

Care and Maintenance of December Birthstone Gold Necklaces

Proper care is essential to preserve the beauty and longevity of December birthstone gold necklaces. Each gemstone has its own specific needs, and understanding these will help ensure that the jewelry remains in pristine condition.

Turquoise: Delicate and Porous

Due to its softness and porosity, turquoise requires gentle care. It should be kept away from acids, perfumes, and lotions, which can damage its surface and alter its color.

To clean turquoise jewelry:

Use a soft, dry cloth to remove dust and dirt
Avoid using water, especially hot water
Do not expose the stone to direct sunlight, which can cause fading
Store it separately from other jewelry to prevent scratching

Turquoise should be worn sparingly and stored in a cool, dry place when not in use.

Tanzanite: Sensitive to Heat and Chemicals

Tanzanite is sensitive to heat and chemicals, so it should be handled with care.

Cleaning tanzanite jewelry:

Use a soft cloth and mild soap to gently clean the stone
Avoid ultrasonic or steam cleaners, which can damage the stone
Store tanzanite away from direct sunlight and heat sources
Remove the jewelry before showering, swimming, or exercising

Tanzanite should be handled with care, especially if it contains inclusions, which can make it more susceptible to damage.

Blue Topaz: Durable and Easy to Care For

Blue topaz is relatively durable and easier to maintain than turquoise or tanzanite.

Cleaning blue topaz jewelry:

Use a soft cloth or a mild soap and water solution
Avoid harsh chemicals, especially chlorine and acids
Store blue topaz separately from other jewelry
Remove the jewelry before swimming or exercising

Blue topaz can be cleaned with ultrasonic or steam cleaners, but it is not necessary for regular maintenance.

Conclusion

December birthstone gold necklaces are a celebration of both tradition and craftsmanship. Whether set with turquoise, tanzanite, or blue topaz, these pieces carry deep historical and cultural significance, as well as gemological and aesthetic value.

Turquoise, with its calming energy and ancient roots, is a symbol of protection and communication. Tanzanite, a modern marvel, is associated with transformation and clarity, and its rarity makes it a treasured gemstone. Blue topaz, with its brilliant color and affordability, is a versatile and accessible option for everyday wear.

When set in 14k or 18k gold, these stones are elevated in beauty and durability, making them perfect for both personal use and gifting. With proper care and appreciation, December birthstone gold necklaces can become cherished heirlooms, passed down through generations.