Although other varieties of spodumene have been known since the 1800s, kunzite was first discovered just over a century ago, making it a relatively new addition to the world of gemstones.
It received its name in honour of Tiffany & Co.’s then-head gemmologist, George Frederick Kunz.
Mostly occurring in various shades of pale pink, kunzite may also be violet to vivid purple in colour. A stand-out feature of this gemstone is its trichroic nature, where different colours may be seen from different crystallographic directions.
This is of particular importance in the cutting process. Because the most intense colour is seen in the direction of the c-axis (the length of the crystal), the stone should be cut with its table facet perpendicular to the c-axis to achieve the best colour.
Kunzite is generally a fairly clean, inclusion- free stone, and is cut deep for maximum colour. However, kunzite has two directions of cleavage – where the stone can split perfectly with the right amount of pressure – making it difficult to cut.
It is also known to be brittle and unpredictable. As a result, many skilful and experienced cutters enjoy the challenge of kunzite, producing beautiful fantasy-cut stones of all kinds.
Another challenging cutting factor is the incredible size of some kunzite crystals.
One notable example is the 3,051-carat specimen named ‘Fragility of the Eternal’ – a fantasy-cut by Victor Tuzlukov, which is believed to be the world’s largest cut kunzite.
Given the fragile nature of this gemstone, it is important to know its best uses in jewellery and suitable cleaning methods.
With a hardness of only 6.5–7 on Mohs’ scale, and its cleavage affecting its durability, kunzite is best suited to jewellery that is less exposed in everyday wear, such as pendants and earrings.
Kunzite is also susceptible to breakage when exposed to a sudden change in temperature and is prone to lose colour when exposed to heat or intense light for long periods of time.
For jewellers, this means avoiding showcasing kunzite in brilliantly lit display cases for too long. To clean this gemstone, warm soapy water is best – avoid the ultrasonic and steam cleaning, and dilute acids when working with this stone.
The best advice when dealing with kunzite is simply to treat it delicately!
Kunzite is often found together with quartz, beryl, and tourmaline, in countries like Brazil, Afghanistan, Madagascar, Myanmar (Burma), Pakistan, and the US. Generally, it is less available than better-known gemstones and more likely to be sourced from specialty suppliers.
A particularly interesting gemmological feature is its fluorescence – a strong yellow-pink to orange colour under long wave ultraviolet light.
To enhance its colour, kunzite may be heat treated or irradiated. This greatly affects the trichroism, resulting in three very similar colours. Kunzite will even change to a bluish green colour after X-ray irradiation, but will revert to its natural colour after only a few hours spent in strong sunlight or being heated to 200°C.
Although synthetic kunzite has been produced, it is not commercially available. Stones that may imitate kunzite include synthetic pink spinel, paste, amethyst, pink topaz, and diopside, all of which can be easily separated by a discerning gemmologist.
Keeping in mind that caution needs to be taken with this stone, kunzite is a great option for a special piece, with an appealing colour and price point suited to a large range of clientele.
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