Iolite is the transparent to translucent gemstone form of the mineral Cordierite, whose popularity has risen in recent times.
The colour of gem-quality Iolite varies from sapphire blue to a violet blue and from light-blue to yellowish-gray. The most pleochroic gemstone, Iolite exhibits a different colour depending on the angle at which it is viewed, with this effect being particularly notable on transparent Iolite gemstones. A blue or violet-blue Iolite gemstone will become a duller gray or grayish-yellow when viewed at a different angle.
Sources: Key sources of Iolite today are India, Australia, Brazil, Canada, Madagascar, Myanmar, Namibia, Sri Lanka, Tanzania and the USA.
Colour palette: Typically light to dark blue and violet, Iolite can also occur in shades of yellow, gray, green or brown. The most desirable colour, however, is an intense violet blue that rivals that of Tanzanite.
Steinheilite refers to blue Iolite, which is named after Fabian Steinheil, a former Russian Governor-General of Finland.
Water-sapphire is a former trade name for Iolite.
More information about the Iolite: Iolite is not a designated Birthstone or Wedding Anniversary gemstone but is associated with vision and creative expression.