Tourmaline & the complicated chemical compositions
(Ca,K,Na, ▢)(Al,Fe,Li,Mg,Mn)3 (Al,Cr, Fe,V)6 (BO3)3 (Si,Al,B)6O18(OH,F)4
The tourmaline chemical formula is one of the most complicated, with its wide range of compositions and varied mineral combinations. This extensive ingredient list of elements creates all the colours of the rainbow.
It can even be multicoloured, as seen in the delightful watermelon tourmaline. Sections cut of this colour-zoned crystal have a juicy pink interior and green outer rind, just like a tasty slice of watermelon.
Tourmaline has an assortment of mixed combinations leading to incredible degrees of colour: we love to call it the lolly-box gemstone!
Tourmaline & the phenomenon of Pleochroism
What is Pleochroism? It’s the science behind how light is absorbed in the crystal structure. As a pleochroic crystal is turned, the different wavelengths of light will absorb differently and give the unusual optical phenomenon of different colours. Interestingly, tourmaline is pleochroic, changing in colour intensity when you turn the crystal.
So, for example, it can appear as vivid dark green from one direction and pale yellow-green from another. Tourmaline is also a great natural polariser (think your polarised sunglasses) due to its unique optic axis. It was used as a handy jeweller’s tool nicknamed ‘tourmaline tongs’, which worked as a rudimental polariscope to identify other gemstones.
Ancient Healing Qualities of tourmaline
Although found in a kaleidoscope of colour, 95% of Tourmaline is actually black. Known as ‘Schorl’, this mysterious gem has been used in ancient native Indian, African and Aboriginal cultures for its magical healing qualities and protection from negative energy.
science Fun Fact - Still got that magic spark!
Schorl is also pyroelectric, meaning it can generate an electric charge. More science fun! In the 18th century, Dutch traders discovered that rubbing schorl quickly causes the stone to become charged—with a positive charge on one end and a negative charge on the opposite side. Basically this worked like a magnet, therefore attracting things on one end and repelling them on the other. After making this discovery, the traders used the positively charged stone to collect the ash from their Meerschaum pipes.
What is the Electric Blue Paraiba gemstone?
The most valuable (and most expensive) in the lolly-box of lovely tourmalines is “Paraiba”, and this stunning gemstone has collectors of rare gems salivating. The spectacular electric blue and neon green colouring are due to copper, unlike any other natural gemstone in its vivid saturation. It was named after the original mining location, Paraiba, in Brazil. Due to the vivid colour and rarity, prices have been known to suprisingly skyrocket to over $10,000 per carat! These delicious coloured gems can now be found in Mozambique and Nigeria, but the argument is that they should not be called “Paraiba” as they aren’t Brazilian in origin.
Frequently asked questions about Tourmaline:
What are the benefits of Tourmaline?
Legends say that black Tourmaline is a terrific healing stone and protects not only the body, the mind, but also emotional and spiritual health. Some have sworn to place it near electrical appliances during use to absorb harmful electromagnetic energy. Especially handy if you are surrounded by laptops, computers, TVs and mobiles and want a little grounding.
What is the hardness of Tourmaline?
7 – 7.5 on the Mohs Scale. This means it has a similar hardness to quartz, like amethyst and citrine. Therefore it is a wonderful gemstone for jewellery.
What type of jewellery is Tourmaline best for?
Tourmaline can be used in all types of jewellery. Considering this delicious gem is comparatively reasonable in price, you can add it to a bracelet, necklace, pendant or earrings for a splash of fun colour.
How do I know the best tourmaline stone for me?
Well firstly, what is your favourite colour? Because this wonderful gemstone is available in a rainbow of colours and is plentiful in deposits, there is a tourmaline for everyone’s taste and budget.
Where can I source the Tourmaline for my jewellery?
At Bell & Brunt, we only use ethically sourced and high-quality gemstones. If you have a particular gemstone in mind, why not reach out and ask our qualified gemmologist?