Seafaring Vikings used iolite to filter the haze and glare from their eyes. The power over the sun aided these fearless warriors in navigating the vast oceans upon which they sailed. The name is from the Greek "los", meaning violet. While it is not as well known as its blue counterparts sapphire and tanzanite, this pleasing blue gemstone is gaining widespread popularity for its beauty and its attractive affordability. More information on Iolite can be found here. 
FACTS
MINERAL: Iolite (Cordierite)
CHEMICAL COMPOSITION: Mg2Al4Si5O18
COLOR: Violetish blue (pleochroic colorless-yellow)
REFRACTIVE INDEX: 1.542 - 1.551
BIREFRINGENCE: +0.045, -0.011
SPECIFIC GRAVITY: 2.61
MOHS HARDNESS: 7.0 – 7.5
-Source AGTA, GIA
$100.00
$175.00
$55.00
$116.55
$132.30
$968.40
$142.20
$165.15
$165.15
$184.05
$186.30
$196.20
$205.20
$227.70
$273.15
$65.00
$65.00
$65.00
$91.35
$97.20
$115.20