December Birthstones

The origin of the birthstone is ancient. It is believed by scholars to date back to biblical times, with the breastplate of Aaron, which contained twelve gemstones representing the twelve tribes of Israel, as described in the book of Exodus.  The first-century Jewish historian Josephus believed there was a connection between the twelve stones in the breastplate, the twelve months of the year, and the twelve signs of the zodiac. A biblical Sherlock Holmes. December birthstones that we have today were a stone of another colour.

In biblical times the rich would buy gemstones assigned to all twelve months wearing them for protection, luck, health and power. Fast forward and we can see how the tradition progressed. For some believers, luck, and healing powers are imbued in the gemstones, in addition to their beauty. For others, they simply honour and adorn the wearer. For others, they are collector’s items and so on.  Humans love to imbue objects with power and magic, as tools for ritual and beliefs.  These days in the Western world we are pretty basic with our birthday beliefs and needs.  People want and need to celebrate themselves and each other for being here on this lovely planet of ours. However contemporary Birthstone gifts are still imbued with a dose of historical meaning and ritual.

In 1912, in an effort to standardize birthstones, the National Association of Jewellers (now called Jewellers of America) met in Kansas and officially adopted a list. The Jewellery Industry Council of America updated the list in 1952 by adding Alexandrite for June, citrine for November and pink tourmaline for October. They also replaced December’s lapis with zircon and switched the primary/alternative gems for March. The American Gem Trade Association added tanzanite as a December birthstone in 2002. In 2016, the American Gem Trade Association and Jewellers of America added spinel as an additional birthstone for August.  Britain’s National Association of Goldsmiths created their own standardized list of birthstones in 1937.

December is the twelfth and final month of the year according to the Julian and Gregorian calendars. December is the beginning of the dark days of winter, yet filled with the celebration, beauty, light and joy that the holidays falling within it bring.

Those born in this month have more than a little competition for the celebration of their birth, but this quandary is harmonized by the fact that December babies have not one but two (in the US there are three) birthstones to choose from.

Tanzanite, turquoise,  make up December’s birthstones in the UK.  These gemstones are both,  known for beautiful shades of blue. In the festive month of lights, these outstanding blues are perfect accessories to the joy the season brings and the celebration of one’s birth.

December Birthstones


As a pleochroic or trichroic (three-coloured) gemstone, each Tanzanite crystal has three colours, blue, purplish-red and greenish-yellow brown (bronze), whose intensity changes when it is viewed from different angles. The most desired colour is a sapphire-esque blue but Tanzanite’s final colour is a combination of its three trichroic hues. While Tanzanite’s colours are typically blues, highly collectable greens, pinks and yellows are also known to exist. Tanzanite exhibits a colour shift (a colour change where the two colours are near each other on the colour wheel) from its blues in daylight, to purples and violets in incandescent lighting. Heat treatment is commonly done to maximise the blue, violet and purple hues although the results can vary between each crystal.



The ideal Turquoise is a sky blue colour of a medium tone and saturation but this gemstone comes in various intensities of blue and greenish-blue. Turquoise is often mottled with veins of its host rock, typically brown limonite or black manganese oxide. As an opaque gemstone, Turquoise is polished as cabochons, with ovals being the most common.