December is the only month in the calendar year that is officially associated with multiple birthstones, a distinction that highlights the richness and diversity of its gemstone selection. These stones—tanzanite, turquoise, zircon, topaz, and lapis lazuli—each offer unique colors, histories, and symbolic meanings, making them treasured choices for jewelry, gifts, and personal adornment. While some of these gemstones are relatively modern discoveries, others have been cherished for thousands of years, linking the December birthstones to both ancient traditions and contemporary aesthetics.
This article provides a comprehensive overview of December’s birthstones, focusing on their geological properties, historical and cultural significance, and their roles in jewelry and personal expression. We will also explore their metaphysical attributes, care instructions, and the reasons behind the inclusion of multiple stones for the month of December.
History and Lore
The tradition of associating gemstones with specific months of the year dates back centuries, with early records found in ancient texts, including the High Priest’s Breastplate from the Bible and the medieval European calendar. These traditions evolved over time, adapting to new discoveries and cultural influences. In the case of December, the inclusion of multiple birthstones reflects both historical practices and modern gemological advancements.
Ancient Roots of December Birthstones
Among the December birthstones, turquoise is one of the oldest and most historically significant. Used by ancient Egyptians, Mesopotamians, and Native Americans, turquoise was valued not only for its striking blue-green color but also for its spiritual and protective properties. It was often carved into amulets, inlays, and jewelry and was believed to ward off evil spirits and bring good fortune.
Lapis lazuli, another traditional December birthstone, has similarly ancient roots. This deep blue stone was highly prized by ancient Egyptians, who used it in jewelry and decorative arts. Cleopatra was said to have worn lapis lazuli cosmetics, and the stone was also used in religious iconography and ceremonial objects.
In contrast, tanzanite is a modern discovery—first identified in Tanzania in the 1960s. Prior to its discovery, the mineral was known as blue zoisite. The name was changed to tanzanite to honor the country where it was found, and it quickly gained popularity for its rare violet-blue hues and trichroism (its ability to display three different colors depending on the angle of light). Its limited geographic source and vibrant color made it a highly desirable gemstone within a short time of its introduction to the market.
The Modern Expansion of December Birthstones
In the 20th century, the list of December birthstones was expanded to include more options, partly due to the discovery of new gemstones and partly to provide greater variety for jewelry design and consumer preference. By the 1960s and 1970s, blue topaz, zircon, and tanzanite were added to the traditional December stones of turquoise and lapis lazuli.
This expansion was driven by the jewelry industry and gemological organizations, which aimed to increase the availability and appeal of December birthstone jewelry. The inclusion of blue topaz, for example, provided a budget-friendly alternative to more expensive stones, while zircon offered a sparkling, diamond-like appearance in a more affordable form.
Today, December is associated with five recognized birthstones: tanzanite, turquoise, zircon, topaz, and lapis lazuli, though the exact list can vary slightly depending on the source and historical context. This flexibility allows for a wide range of personalized jewelry options, catering to different tastes, budgets, and symbolic preferences.
Geological Formation and Sources
The geological properties and origins of December’s birthstones are as varied as their colors and meanings. Each gemstone forms under unique conditions and is found in specific geographic locations.
Tanzanite
Tanzanite is a trigonal mineral composed primarily of zinc aluminum silicate. Its violet-blue color is due to trivalent iron impurities and its trichroic nature, meaning it can display three different colors when viewed from different angles. This gemstone is only found in one location on Earth: the Simanjiro Plateau in Tanzania, near the Serengeti National Park and Mount Kilimanjaro. The mining area is extremely limited—only about 4.3 miles by 1.2 miles—making tanzanite one of the rarest naturally occurring gemstones in the world.
Because of its limited source and increasing rarity, tanzanite is considered a finite resource. Its value has steadily increased over time, especially as mining becomes more difficult and deposits are depleted.
Turquoise
Turquoise is an amorphous phosphate mineral composed of copper and aluminum. It forms in arid regions, typically in weathered copper deposits, where water percolates through the rock and precipitates the mineral. This process is known as hydrothermal alteration.
Historically, Persian turquoise from Iran was the most famous source, but today, American turquoise from Arizona, Nevada, and New Mexico is highly prized. Other notable sources include China, Egypt, and Mexico. Each location produces turquoise with distinctive color variations and matrix patterns, making it a popular choice for handcrafted jewelry and tribal designs.
Zircon
Zircon is a zirconium silicate that occurs in a wide range of colors, from colorless and yellow to red and blue. The blue zircon, a popular December birthstone, is created through heat treatment, which transforms the natural brown or red zircon into a vibrant blue. This process was developed in the mid-20th century and is now a standard practice in gemstone enhancement.
Zircon is found in many parts of the world, including Australia, Brazil, Cambodia, and Sri Lanka. It is known for its high refractive index and dispersion, which gives it a sparkling, diamond-like appearance, especially in well-cut stones.
Topaz
Topaz is a silicate mineral known for its range of colors, including blue, yellow, pink, and brown. Blue topaz, the December birthstone variant, is typically heat-treated to enhance or change its color, especially to achieve the sky-blue or London blue hues that are most popular.
Natural blue topaz is rare, so most of the blue topaz in the market is treated. The gemstone is found in Brazil, Mexico, and the United States, and it is relatively abundant, making it a cost-effective option for jewelry.
Lapis Lazuli
Lapis lazuli is a metamorphic rock composed primarily of lazurite, a deep blue mineral, along with calcite, pyrite, and other minerals. It forms under high-pressure conditions in ancient geological formations, typically in alkaline rocks. The most famous sources of lapis lazuli are Afghanistan, where it has been mined for millennia, and Bolivia and Russia.
Lapis lazuli is not technically a gemstone in the traditional sense, as it is opaque and composed of multiple minerals, but it is included among December’s birthstones due to its historical significance and aesthetic appeal.
Gemological Properties
Understanding the gemological properties of December’s birthstones helps in identifying authentic stones, assessing their value, and caring for them properly. Below is a detailed overview of the key properties of each gemstone.
Tanzanite
| Property | Value |
|---|---|
| Chemical Formula | ZnAl2(SiO4)O(OH) |
| Color | Violet-blue, blue, and purple (trichroic) |
| Hardness (Mohs) | 6–7 |
| Refractive Index | 1.694–1.703 |
| Specific Gravity | 3.10–3.35 |
| Cleavage | Poor to indistinct |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Origin | Tanzania |
| Treatments | Heat treatment to enhance color |
Tanzanite is known for its vibrant color and trichroism, making it a highly desirable gemstone. Its relatively low hardness (6–7 on the Mohs scale) means it should be handled with care to avoid scratches or chips.
Turquoise
| Property | Value |
|---|---|
| Chemical Formula | CuAl6(PO4)4(OH)8·4H2O |
| Color | Blue to green, often with a matrix pattern |
| Hardness (Mohs) | 5–6 |
| Refractive Index | 1.61–1.65 |
| Specific Gravity | 2.6–2.8 |
| Cleavage | None |
| Luster | Waxy to greasy |
| Transparency | Opaque |
| Origin | Iran, USA, China, Mexico |
| Treatments | Stabilization, dyeing, oiling |
Turquoise is soft and porous, which makes it susceptible to damage from acids and moisture. It is often stabilized or dyed to enhance its color and durability.
Zircon
| Property | Value |
|---|---|
| Chemical Formula | ZrSiO4 |
| Color | Colorless, yellow, red, blue |
| Hardness (Mohs) | 6–7.5 |
| Refractive Index | 1.92–2.00 |
| Specific Gravity | 4.6–4.7 |
| Cleavage | Poor |
| Luster | Vitreous |
| Transparency | Transparent |
| Origin | Australia, Cambodia, Sri Lanka |
| Treatments | Heat treatment to produce blue color |
Zircon is known for its high refractive index, which gives it a brilliant sparkle, especially in well-cut and treated stones.
Topaz
| Property | Value |
|---|---|
| Chemical Formula | Al2SiO4(F,OH)2 |
| Color | Colorless, blue, yellow, pink |
| Hardness (Mohs) | 8 |
| Refractive Index | 1.618–1.627 |
| Specific Gravity | 3.4–3.6 |
| Cleavage | Perfect |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Origin | Brazil, Mexico, USA |
| Treatments | Heat treatment to enhance color |
Topaz is relatively hard and durable, but it has perfect cleavage, so it should be protected from hard impacts.
Lapis Lazuli
| Property | Value |
|---|---|
| Chemical Composition | Lazurite (main mineral), with calcite and pyrite |
| Color | Deep blue with white streaks and golden pyrite flecks |
| Hardness (Mohs) | 5–6 |
| Refractive Index | 1.50–1.70 |
| Specific Gravity | 2.4–2.9 |
| Cleavage | None |
| Luster | Waxy to dull |
| Transparency | Opaque |
| Origin | Afghanistan, Bolivia, Russia |
| Treatments | Oiling and waxing to enhance luster |
Lapis lazuli is not a true gemstone, but it is included as a December birthstone due to its historical and cultural significance. It is opaque and often carved or inlaid in jewelry and decorative objects.
Symbolism and Metaphysical Beliefs
Each of December’s birthstones has been associated with various symbolic meanings and metaphysical properties across different cultures and time periods. These beliefs, while not scientifically proven, have contributed to the enduring popularity of these gemstones.
Tanzanite
Tanzanite is often associated with inner peace, wisdom, and emotional healing. It is believed to enhance spiritual awareness and promote emotional balance. Some metaphysical practitioners suggest that tanzanite helps in overcoming grief and trauma, making it a comforting stone for those undergoing difficult life transitions.
Its rarity and deep blue-violet color also make it a symbol of transformation, intuition, and the opening of the third eye chakra, which is associated with vision and inner wisdom.
Turquoise
Turquoise has long been considered a stone of protection, good fortune, and calmness. In Native American traditions, it is believed to ward off negative energy and attract positive vibrations. It is also associated with healing, communication, and emotional stability.
In ancient Egypt, turquoise was used in amulets and jewelry to protect the wearer from harm and to ensure a prosperous life. Its greenish-blue color is often linked to nature, serenity, and the connection between the earth and sky.
Zircon
Zircon is associated with wisdom, clarity, and spiritual awakening. It is believed to enhance memory and promote mental clarity, making it a popular stone for students and scholars. Zircon is also thought to protect against psychic attacks and to encourage positive thoughts and emotions.
The sparkling blue zircon is particularly valued for its ability to bring joy and optimism, making it a symbol of hope and renewal.
Topaz
Topaz is a stone of strength, vitality, and emotional healing. It is often used to boost confidence, reduce stress, and enhance emotional stability. Blue topaz, in particular, is associated with calmness, peace, and the ability to overcome challenges with grace and resilience.
In ancient times, topaz was believed to protect against enchantments and to bring happiness and prosperity to the wearer.
Lapis Lazuli
Lapis lazuli has been used for spiritual and philosophical purposes for thousands of years. It is associated with truth, wisdom, and the ability to communicate effectively. It is believed to stimulate the third eye and throat chakras, enhancing intuition, creativity, and self-expression.
The deep blue color of lapis lazuli is also symbolic of the night sky, cosmic consciousness, and the mysteries of the universe. It has been used in art, meditation, and spiritual rituals to foster inner peace and enlightenment.
Care and Cleaning
Proper care is essential to maintaining the beauty and longevity of December’s birthstone jewelry. Each gemstone has different hardness levels and sensitivities, so it's important to store and clean them appropriately.
General Care Tips
- Avoid exposure to harsh chemicals, including household cleaners and perfumes.
- Store gemstones separately to prevent scratches, especially softer stones like turquoise and lapis lazuli.
- Remove jewelry during physical activities to avoid damage from impact or abrasion.
- Clean gemstones with a soft cloth and mild soap in warm water. Avoid using ultrasonic cleaners or steamers unless specified for the stone.
Specific Care for Each Birthstone
Tanzanite
- Soft and sensitive to heat and light, tanzanite should be stored in a cool, dark place.
- Use a soft cloth and mild soap to clean, avoiding harsh chemicals.
Turquoise
- Very porous and sensitive to moisture and acids.
- Clean with a dry or slightly damp cloth; avoid submerging in water.
- Avoid exposure to perfumes, lotions, and acidic substances.
Zircon
- Relatively durable but sensitive to heat.
- Clean with warm, soapy water and a soft brush.
- Avoid high heat, which can alter its color.
Topaz
- Hard and durable, but it has perfect cleavage, so it is susceptible to chipping.
- Clean with warm, soapy water and a soft brush.
- Avoid hard impacts.
Lapis Lazuli
- Soft and opaque, it should be polished and oiled occasionally.
- Avoid exposure to chemicals and abrasive cleaners.
Conclusion
December’s birthstones offer a rich tapestry of colors, histories, and meanings, making them unique and meaningful choices for jewelry and personal adornment. From the rare and trichroic tanzanite to the ancient and protective turquoise, each gemstone tells a story that spans thousands of years and multiple cultures.
Whether you are drawn to the sparkling clarity of zircon, the vibrant energy of blue topaz, the earthy charm of turquoise, or the spiritual depth of lapis lazuli, December’s birthstones provide a diverse and meaningful selection that can reflect your personal style and values.
As the only month with multiple birthstones, December offers the flexibility to choose a stone that resonates with your personality, your aesthetic, and your connection to nature, history, and spirituality. Whether you wear it as a ring, pendant, or bracelet, a December birthstone is more than just a piece of jewelry—it is a symbol of your identity and a celebration of your birth month.