|
 |
|
| Color |
|
Medium to dark purplish
blue |
|
|
|
| Gem Family |
|
Iolite is the gem form
of the mineral corderite. |
|
|
|
| Source |
|
Iolite is mined in India,
Sri Lanka, Madagascar, Zimbabwe, and Brazil. The
Vikings probably mined iolite from deposits in Norway
and Greenland. |
|
|
|
| Clarity |
|
Ranges from no visible
inclusions to moderately included. |
|
|
|
| Size Range |
|
0.5 carat to 3 carats.
It is more common to find iolite with beautiful
blue below a carat in size: larger sizes are often
too dark or show a brown secondary tone. |
|
|
|
| Shapes Available |
|
Ovals, cushions, trillions,
rounds, barions and emerald brilliant cuts are available. |
|
|
|
| Enhancement |
|
Iolite is not treated:
the color is natural, exactly as it is found in
the earth. |
|
|
|
| Lore & History |
|
The name iolite comes
from the Greek ios, which means violet. Iolite is
usually a purplish blue when cut properly, with
a softness to the color that can be quite attractive.
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
position, they relied on iolite to help them determine
their location. 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. |
|
|
|
| Toughness &
Hardness |
|
Iolite is relatively
hard, with a Mohs Hardness of 7 to 7.5, but should
be protected from blows. |
|
|
|
| Care & Cleaning |
|
Clean with mild dish
soap: use a toothbrush to scrub behind the stone
where dust can collect. |
|
|
|
| Price Range |
|
$30 to $150 per carat |
|
|
|
| Special Characteristics |
|
The property that made
iolite so valuable to the Vikings is extreme pleochroism.
Iolite displays different colors in different directions
in the crystal. A cube cut from iolite will look
a violetish blue almost like sapphire from one side,
clear as water from the other, and a honey yellow
from the top. This property led some people to call
iolite "water sapphire" in the past, a name that
is now obsolete. Pleochroism may have been helpful
in navigation but it makes things difficult for
a gem cutter. If iolite is not cut from exactly
the right direction, no matter the shape of the
rough, its color will not show to its best advantage,
since the blue is mixed with yellow and brown. Fine
gems show only the violet-blue colors. |
