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December born babies are lucky as they have three official birthstones; tanzanite, zircon, and turquoise. Tanzanite is valued for its blue-violet colour, zircon for its high refraction, and turquoise for its use in jewellery across many ancient civilizations. From the oldest on earth, to one of the first used in jewellery, and finally to one of the most recently discovered, all December’s birthstones are truly noteworthy.
The traditional December birthstone is turquoise, however over time both blue zircon and tanzanite have been added. All of these birthstones have blue tones and have their own timeless appeal.
In 1870 Tiffany & Co released a ‘Gregorian Birthstone Poems‘ booklet. It listed Turquoise as the birthstone for December;
“If cold December gave you birth,
The month of snow and ice and mirth,
Place on your hand a turquoise blue;
Success will bless whate’er you do.”
In 1912 turquoise as the December birthstone was also adopted by the Jewellers of America Association.
It wasn’t until 1952 that zircon (primarily blue zircon) was added as an alternative to turquoise.
Finally, in 2002 Tanzanite was added as the final birthstone for December.
Turquoise has been mined since at least 3000BC and features heavily in ancient Egyptian jewellery and artefacts. They called it ‘mefkat’, meaning ‘joy’. The Ancient Persians, Greeks and Romans also used turquoise in their jewellery, religious buildings, and weapons. Turquoise was also a popular stone in the Americas; the Aztecs believed it was passed down by the creator god Quetzalcoatl who was a feathered serpent and protector of goldsmiths and craftsmen alike.
Turquoise is a hydrated copper aluminum sulphate mineral comprised of microscopic crystals. It forms in dry places where acidic, copper rich groundwater is able to penetrate minerals containing phosphorus and aluminum.
It is generally blue in colour from the copper content, but different impurities can cause it to form in other colours. Green tones come from vanadium or chromium, yellow from iron and in some rarer cases purple can be caused by strontium in the chemical structure.
Turquoise may also have ‘matrix’ through the stone, which are inclusions of the host rock that the turquoise has formed in. They often have a vein-like appearance and can differ in colour from brown, black to yellow.
Turquoise is found worldwide, with the most prolific mining activity occurring in the U.S and China. Today Arizona and Nevada produce the most turquoise in the US, with the famous Kingman mine producing fine blue turquoise, although the US has over 300 listed sources of turquoise in the west. China produces the most turquoise annually, but generally is more green in colour and tends to have more matrix through it.
The top turquoise colour is duck-egg blue or sky blue that traditionally came from Iran, coined ‘Persian Blue’. It was a solid blue without any matrix throughout the stone. Today these terms are used to describe this top quality turquoise regardless of the source. Similarly, Arizona produces a solid light blue turquoise of high quality called ‘Sleeping Beauty Turquoise’.
Generally matrix within turquoise lowers its value, but a certain matrix pattern called ‘spiderweb’ is highly sought after.
Turquoise is a softer stone measuring 5-6 on the Mohs scale, however most turquoise on the market has been stabilised by resins or fillers which helps it wear better. Turquoise is also porous, meaning it will readily soak up chemicals; even prolonged exposure to cosmetics and sweat can discolour or damage the stone.
Keep your turquoise away from high temperatures as it may cause breakage. Clean your turquoise pieces with warm soapy water and a soft brush only – never use ultrasonic and steam cleaners.
Zircon is the oldest known mineral on Earth! Scientists dated Australian zircons to be more than 4.4 billion years old, meaning they were around well before the dinosaurs and any complex organisms. Zircon helped pave the way for a branch of science called geochronology which looks at dating items using trace elements such as uranium found in geological formations.
No, they are two different gemstones. Zircon is a naturally occurring form of zirconium silicate (ZrSiO4), whereas Cubic Zirconia is a synthetic stone comprised of zirconium dioxide. Zircons come in many tones from red, orange, pink, yellow, colourless and blue. Cubic zirconia is often produced as a colourless synthetic stone to imitate diamonds, although it may come in almost any other colour. Zircon is genuinely valuable as a natural stone, whereas cubic zirconia does not have a lasting value as it is mass produced, man-made stone.
Zircons come various colours, with blue zircon being one of the most popular colours. Blue zircon is often heat treated to produce the colour. Common, but still beautiful colours are champagne, red, yellow and colourless, with some of these colours undergoing heat treatment also. Australian zircons are not often heat treated as they are already vibrant, bright stones. Rarer colours include green and purple, with the Hartz Ranges producing highly sought-after lilac or mauve zircons which can attract high prices, especially in larger sizes.
Zircon has been used for over 2000 years, with its rich history also leading to the isolation of the metal zirconium by Jons Jacob Berezelius in 1824. Zirconium is commonly used as a metal on men’s wedding rings for a point of difference as when it is oxidised it turns a black colour.
Blue zircon has been popular for many centuries, with its height in popularity occurring in Victorian era jewellery. However colourless zircon has had a more difficult time as it was often used as a substitute for diamonds in the early 1900s, leading to distrust with this form of the gemstone.
During medieval times it was believed to help the wearer get a good nights sleep and provide protection. Today its symbolic meaning is to success and wisdom.
Zircon is 7.5 on the Mohs scale, but is known to be brittle so it can be abraded easily. Always take off your zircon rings while doing manual labour as constant bumps can dull your stone over time. To clean your zircon jewellery use warm water with a mild dishwashing liquid and a soft brush.
Tanzanite is a variety of the mineral zoisite that is known for its strong pleochroism and blue-violet hues. It is often heat treated to bring out these blue and violet colours- this is a permanent treatment so will not fade or discolour over time. Unheated Tanzanite is nicknamed Mermaid Tanzanite are becoming more common in the market; they often feature green, blue and purple tones when viewed from different angles.
As well as one of December’s birthstones, Tanzanite is also the gemstone for the 24th wedding anniversary.
Tanzanite is one of the most recently discovered gemstones in the world. In 1962 blue stones from Tanzania were identified as the mineral zoisite. In the following years they searched for the source of these stones and in 1967 they were found in only a 50km square area in the Merelani Hills, near Mount Kilimanjaro; the volcano believed to have played a role in the creation of this stone over 500 million years ago. This is the only source of tanzanite in the world. Tiffany & Company recognised this as the next big coloured gemstone and made a partnership to become the main seller of the stone ‘Tanzanite’, named by Tiffany & Co. after the country it was from.
One of the most impressive tanzanites in the world is the ‘Queen of Kilimanjaro’. It is a 242ct stone set into a stunning 18ct white gold tiara accented with over 800 green tsavorite garnets and over 900 diamonds. It is currently housed in a private collection.
Tanzanite is only 6 to 7 on the Mohs scale so it is best suited to dress rings or earrings and pendants as it is more susceptible to damage than a diamond or sapphire. It may crack if exposed to high heat or sudden extreme temperature changes so avoid the use of ultrasonic cleaners or steam cleaners. It also may be damaged by strong chemicals such as hydrochloric and hydrofluoric acids. To keep your tanzanite clean use a soft brush with warm soapy water.
It’s important to consider your lifestyle, colour preferences and budget when picking your favourite December birthstone jewellery, but ultimately the decision is up to you. We are hopeful this table will help you narrow down your choice.
| Properties | Turquoise | Blue Zircon | Tanzanite |
|---|---|---|---|
| Moh's Scale (Hardness) | 5 to 6 | 7.5 | 6 to 7 |
| Colours | Blue, green, sometimes purple. Often with matrix through the stone. Duck egg or 'Persian blue' most sought after. | Red, orange, yellow, green, brown, colourless, pink and blue. Blue almost always heated. | Blue and purple with green and brown from certain angles. Most blue and purple stones on the market are heated. |
| Localities | America, China main producers today | Australia, Cambodia, Madagascar, Sri Lanka, Thailand | Tanzania |
At Diamondport Jewellers we have a range of coloured gemstone jewellery ready to wear, or alternatively we can custom design and make your dream turquoise, zircon or tanzanite piece. Shop in stock pieces below, or book a consultation with one of our experts.
December birthstones offer a diverse range of blues tones and stone types to suit a wide range of designs and budgets. At Diamondport Jewellers we invite you to explore the possibilities these sensational December birthstones offer in our private studio setting today.
Book your private consultation today, and let our skilled jewellers create a piece of jewellery as unique as you.
