Iolite
AN AFFORDABLE GEM TO COMPLEMENT THE RICH BLUES FROM DENIM TO VELVET SO PREVALENT IN FASHION.
Iolite is a blue or blue-violet lovely gemstone with a pleochroism that allows multiple colour shades to be seen in the same gem. Iolite is trichoric exhibhiting three colours when viewed from different angles.It has rich blue to violet blue from one side ,clear as water from the other,and as gold as honey from the other side.This water like transparency amid blue hues is the reason that iolite is sometimes known as water sapphire.Its true name iolite comes from the Greek word ios ,which means violet.Another old name is dichroite ,a Greek word meaning “two coloured rock”, a reference to corderite’s strong pleochroism.
Iolite only officially named in 1912, has been used and admired for centuries.It was very popular in jewellery in the 18th century.In todays jewelry market it is regaining its popularity for its beauty and its attractive affordability.The iolite’s colour range of blue,blue-violet competes for public attention with sapphire,tanzanite .
Unlike many other popular gems iolite cannot be heat treated to enhance its colour.The colour you see is the natural colour of the gemstone when it was first discovered.This adds value to many gem buyers who do not want a treated gemstone.
Inclusions seen in iolite vary considerably, but there is one notable variety seen: thin hexagonal platelets of either hematite or goethite that give the stone red spots . A very rare variet of iolite also known as blood shot iolite.
Pleochroism makes difficulty for the gem cutter to properly orient the rich blue colour on the table/top of the gem.If iolite is not cut from exactly the right direction its colour will not show to its best advantage.If cut properly,the gem displays a brilliant violet when viewed from above ,but may appear colourless from another angle and yellow to honey yellow from another angle.
In addition to creating array of colours ,pleochroism offers another use to iolite. The stone was once known as Viking compass because it can determine the direction of the sun on overcast days.When Leif Eriksson and the other legendary Viking explorers ventured far out into the Atlantic Ocean,they used thin pieces of iolite as the world’s first polarizing filter.Looking through an iolite lens,they could determine the exact position of the sun and navigate safely to the new world and back.