December Birthstones: Tanzanite vs Blue Zircon, Which One to Choose?
December is the only month with three traditional birthstones: turquoise, zircon and tanzanite. For fine jewelry, the choice usually comes down to two blue gems. Comparing the December birthstone options side by side, tanzanite and blue zircon both offer a captivating blue, yet they are entirely different stones with their own character, strengths and ideal uses.
This guide compares them on origin, color, brilliance, durability and value, to help you choose the right stone for a December birthday or a festive gift.
Tanzanite: The Violet-Blue Gem From a Single Source
Tanzanite is a blue to violet variety of the mineral zoisite. It was discovered in 1967 in northern Tanzania, near Mount Kilimanjaro, and to this day that small area remains the only known commercial source in the world. This unique origin is one of the reasons tanzanite fascinates collectors. It was added to the list of December birthstones in 2002, making it the most recent addition. Discover its full history in our story of tanzanites.
Its most striking feature is trichroism: depending on the angle, tanzanite reveals blue, violet and sometimes burgundy flashes. The result is a velvety, deep color that looks especially rich under evening light.
Blue Zircon: The Natural Gem With Exceptional Fire
Zircon is a natural zirconium silicate and one of the oldest minerals on Earth: some zircon crystals are more than four billion years old. It exists in many colors, but blue zircon is the most sought after for jewelry. It should never be confused with cubic zirconia, a synthetic imitation; we explain the difference in blue zircon vs cubic zirconia.
Blue zircon is prized for its brilliance and dispersion, the ability to split light into flashes of color, which give it a fire close to that of diamond. Its color ranges from light sky blue to intense electric teal. Read more in our story of blue zircon.
Tanzanite vs Blue Zircon: Side-by-Side Comparison
Color
Tanzanite is deep and velvety, between blue and violet, with a noble, almost nocturnal presence. Blue zircon is brighter and more luminous, with a cooler, electric blue that evokes a swimming pool or a winter sky. If she loves dark, mysterious tones, choose tanzanite. If she prefers sparkling, luminous blues, choose blue zircon.
Brilliance
Blue zircon clearly wins on brilliance and fire. Its high refractive index and strong dispersion make it one of the liveliest colored gems. Tanzanite shines through the depth and play of its color rather than its sparkle.
Durability
Both stones require some care. Tanzanite has a hardness of around 6 to 6.5 on the Mohs scale, which makes it better suited to pendants and earrings than to rings worn during demanding activities. Blue zircon is slightly harder, around 6.5 to 7.5, but its facet edges can wear over time if it is knocked against hard surfaces. For daily wear, pendants and earrings are ideal for both.
Rarity and Price
Tanzanite's single source makes it rare in absolute terms, and fine, saturated stones command a significant price. Our tanzanite price guide explains how it is valued compared to sapphire. Blue zircon is generally more accessible at equivalent size, while offering exceptional visual impact.
Symbolism
Tanzanite is often associated with transformation and new beginnings, fitting for the end of the year. Blue zircon is traditionally linked to wisdom, prosperity and peace of mind.
Which December Birthstone Should You Choose?
Choose Tanzanite If
She loves deep, sophisticated colors, appreciates rarity and unique origins, and prefers a piece with a quiet elegance. The Crush Nova pendant with tanzanite and blue sapphires and the Crush Nova earrings in tanzanite and blue sapphires are perfect December gifts. For a statement, the Crush Nova ring is best worn for occasions. Explore the full tanzanite jewelry collection.
Choose Blue Zircon If
She loves brilliance, bright colors and a joyful look. Blue zircon is paired with pink sapphires on the Crush Nova pendant, the Crush Nova earrings and the Crush Nova ring, a vibrant pairing of blue and pink. If she likes asymmetry, the single earring is a modern option.
Still Hesitating?
Compare these stones with other blue gems in our guides on tanzanite vs blue sapphire and blue zircon vs blue topaz vs aquamarine. Our team can also advise you through the contact page.
Caring for Tanzanite and Blue Zircon
Clean both stones gently with lukewarm soapy water and a soft brush. Avoid ultrasonic and steam cleaners, as well as sudden temperature changes. Store each piece separately in a soft pouch to protect it from harder stones. More advice in our jewelry care guide.
Summary
Tanzanite and blue zircon are the two most beautiful December birthstones for fine jewelry. Tanzanite, a zoisite found in a single region of Tanzania, offers a deep, velvety violet-blue and remarkable rarity. Blue zircon, a natural gem not to be confused with cubic zirconia, dazzles with its brilliance and luminous electric blue. Choose tanzanite for depth and rarity, blue zircon for fire and radiance, and favor pendants and earrings for everyday wear.
