December Birthstones: Tanzanite, Turquoise & Zircon

Updated on February 22, 2024 by Manisha Talagala

Birthstones can be a meaningful gift for your loved one during a special occasion, and December’s gemstones - tanzanite, zircon and turquoise - are best known for their vivid shades of blue. Despite being relatively inexpensive, their beauty is unmatched and they can replace precious stones like diamonds or sapphires.

If you wish to discover more about these three beautiful gemstones, keep reading.

Tanzanite

An amazing blue-purple variety of the mineral zoisite, tanzanite can only be found under the shadow of Mount Kilimanjaro - the Merelani Hills - in Tanzania. Discovered in 1967, it has since quickly risen to popularity: thanks to its deep blue colour and limited supply, tanzanite is a favourite among customers.

Tanzanite is resistant to the effects of normal heat, light and common chemicals. Still, it may crack if exposed to very high temperatures or sudden temperature changes. Usually, most tanzanite is brownish zoisite, which is then heated to obtain the blue to violet hues that make this gemstone so unique.

If you want to clean your tanzanite jewellery, warm and soapy water is what you should opt for.

Turquoise

A gemstone loved since ancient times, the turquoise was thought to possess many beneficial powers, such as granting health and good fortune. The turquoise is a semi-translucent to opaque gem that ranges from blue to green and often has veins of matrix running through it, which are remnants of limonite or sandstone - turquoise’s host rocks.

The presence of matrix can lower the value of turquoise, but that doesn’t mean it is unmarketable. Some people prefer the presence of matrix, especially when it comes to spiderweb turquoise, which contains matrix in thin, web-like patterns across the gemstone.

Nishapur district in Iran, is where the most precious Persian Blue turquoise has been mined for more than 1000 years. Today, China produces 75% of turquoise, alongside Iran, the US, Mexico, Chile and Tibet.

Zircon

Zircon has been used for almost 2000 years throughout history, and it comes in different colours: most natural zircons are yellow, brown or red. Several other colours do exist, such as green, blue and colourless zircons which are produced by heating and irradiating the gemstone.

Nowadays, 80% of the zircons sold are blue, making it the best selling colour.

Thanks to their brilliance and flashes of multicoloured light, called fire, colourless zircons are even considered to be popular and fraudulent lower-cost alternatives to diamonds.

Some zircons pick up small amounts of radioactive uranium and thorium during their growth, and with time the radiation breaks down the crystal structure. These zircons - usually green - become metamict (zircons that have lost their crystalline structure and become amorphous due to radiation).

Zircons are classed as high, intermediate/medium, or low based on their level of deterioration.