Iolite

Iolite (pronounced eye-oh-light) is formed when primarily aluminum, magnesium and iron undergo a metamorphic process in which layers accumulate over time which accrues significant heat and pressure to combine these elements together forming a new mineral and crystalizing. Many gems in the trade are heat treated or irradiated to bring out their natural color, however Iolite is one of the few gems that comes right out the ground a gorgeous intense purple color without any treatment! It tends to resemble the color of Tanzanite but more purple and less periwinkle. Iolite is pleochroic meaning multiple colors can be viewed at different angles, sometimes subtly and Tanzanite is trichroic meaning three distinct colors can be viewed at different angles

Hardness: 7 – 7.5
Composition: Mg₂Al₄Si₅O₁₈