When
Leif Eriksson and the other legendary Viking explorers ventured far
out into the Atlantic Ocean, away from any coastline that could help
them determine their position, they had a secret gem weapon: Iolite.
The Viking mariners used thin pieces of it as the world's first polarising
filter. Looking through an Iolite
lens, they were able to determine the exact position of the sun, and
navigate their way safely to the New World and back.
The
property that made Iolite
so valuable to the Vikings is its extreme pleochroism. Iolite
has different colours in different directions in the crystal. A cube
cut from Iolite will
look a more or less violet blue, almost like sapphire, from one side,
clear as water from the other, and a honey yellow from on top. In
the past, this property led some people to call Iolite
'water sapphire', though the name is now obsolete.
Pleochroism
may have been helpful in navigation but it certainly makes life difficult
for the cutter. If Iolite
is not cut from exactly the right direction, no matter what the shape
of the raw crystal, its colour will not be shown to its best advantage.
The
name Iolite comes from
the Greek 'ion', which means violet. Iolite
is usually a purplish blue when cut properly, with a softness to the
colour that can be quite attractive.
Iolite
is readily available and surprisingly affordable. The richer the blue,
the better. It is mined in India, Sri Lanka, Mozambique, Zimbabwe,
and Brazil. The Vikings probably mined theirs from deposits in Norway
and Greenland.
Iolite
is relatively hard but should be protected from blows. With its attractive
colour and reasonable price, it may become a jewellery staple in the
future.
Pictured
on this page:
5 LB - IOLITE ROUGH
LOT FROM INDIA
I
ACQUIRED THIS MATERIAL IS FROM INDIA. THE PIECES ARE QUITE LARGE
IN SIZE. THE LOT WEIGHTS 5 POUNDS. THE MATERIAL IS PURPLE BLUE
IN COLOR AND HAS SOME CLEAN AREAS SUITABLE FOR CABBING AND CUTTING.
I
cut a few of these stones and though they are blue, they demonstrate
an appearence of crystalline fire when viewed in good lighting
such as the sun. Beautiful stones!
Art,
Passion, and Life
