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Alice Rochester
29th August 2007 13:14

Iolite

 

Hi! It's Alice again! I've been doing some research into the lovely and unusual stone, iolite, which I thought you might be interested in.

Iolite is actually the gem quality version of Corderite, which was named after the French geologist Pierre L.A. Cordier, who first described it in 1813. It is also known as "water sapphire" because of its lovely pale bluish colours that can vary from violet to a blue-green or grey.

Iolite is pleochroic, which means it shows different colours (in this case, three) when viewed from different angles. The best blue colour is seen when viewed down the length of the crystal; when viewed across the crystal it can appear almost colourless. Tanzanite is a blue-violet gemstone variety of the mineral zoisite, has strong pleochroism as well and can be easily confused with iolite. However, tanzanite is usually more strongly coloured, its pleochroic colours vary from dark blue, green-yellow and red-purple and it has greater fire. The pleochroism exhibited in both these stones makes a gem cutter's job very hard work!

Iolites are fairly brittle, exhibiting conchoidal tendencies (breakages look like sea shells) or uneven fractures, so they are also difficult to find in square cuts like baguettes and princess cuts, and in larger sizes. Most other cuts are fairly widely available. Highly facetted cuts like the brilliant are particularly good for pale stones like iolite as they seem to concentrate the colour, making it look stronger, darker, and more sparkly.

We can get iolite down to around 2mm in size but we wouldn't recommend setting pieces this size in rings because of its frailty, particularly where the stones are set around the back of the finger as in some eternity rings. A harder stone that could replace it is a pale blue sapphire, although in these smaller sizes it will be difficult to reproduce the lilac-y shades that are seen in iolite.

This is one of my favourite commissions we have made using iolite – it was designed by Becky.

18ct white and rose gold engagement ring with trillion Iolite

These pieces are currently in our ready to wear collection:

Faceted iolite and Sterling silver earrings Iolite & Sterling silver spheres pendant on a chain drop A chalcedony and iolite pendant on a 20" sterling silver chain

And this gorgeous twist ring is in our Purple Label collection:

Solid silver twist ring with faceted pink tourmaline

Iolite is found in Sri Lanka and Myanmar primarily, but large, flawless pieces have also been found on Garnet Island in Canada. Some are up to 5cm long! Iolite is also found in Madagascar, Tanzania, Brazil and South Africa.

Interestingly, when Viking explorers ventured out into the Atlantic Ocean, far away from any coastline, it is said iolite was their secret gem weapon; they used thin pieces of iolite as the world's first polarizing filter. Looking through an iolite lens, they could determine the position of the sun, helping them to navigate safely.

Iolite is believed to be the gemstone of happiness and joy. It is also believed to possess Feng Shui properties that help build relationships with others. For people who believe in these things, iolite is supposed to cure sore throat, varicose veins and various skin eruptions and blisters.

Interesting links:

Bye for now!

Alice Rochester
 

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  • Harriet Kelsall Jewellery Design, North Barn, Fairclough Hall Farm, Halls Green, Weston, Hertfordshire, SG4 7DP, England
    Phone: +44 (0)1462 790565 Fax: +44 (0)1462 790140 enquiries@hkjewellery.co.uk
  • Harriet Kelsall Jewellery Design, 6/7 Green Street, Cambridge, Cambridgeshire, CB2 3JU, England.
    Phone: +44 (0)1223 461333 Fax: +44 (0)1223 365269 cambridge@hkjewellery.co.uk

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