IOLITE


All facts and figures taken from the GIA

IOLITE

Green in sunlight. Red in lamplight. Color-changing alexandrite is nature’s magic trick. Often described by gem aficionados as “emerald by day, ruby by night,” alexandrite is the very rare color-change variety of the mineral chrysoberyl. Originally discovered in Russia’s Ural Mountains in the 1830s, it’s now found in Sri Lanka, East Africa, and Brazil, but fine material is exceptionally rare and valuable.


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


Iolite is the gemstone for the twenty-first wedding anniversary.

FOUND WHERE

Precious_Gemstone_Where_Found_Iolite