Kunzite

Kunzite is the pink to lilac-violet gem variety of spodumene, a lithium aluminum silicate. Its color is caused by traces of manganese, and it was named in 1902 after gemologist George Frederick Kunz.

Kunzite is strongly pleochroic, showing its most intense color when viewed down the length of the crystal, which guides how cutters orient it. The color can be pale and is sensitive to strong light and heat, sometimes fading over time.

It belongs to the same mineral family as the green gem hiddenite. Crystals are often large and flat with vertical striations, and the species is also an important lithium ore.

Kunzite forms in lithium-rich granite pegmatites, the same coarse-grained igneous bodies that produce tourmaline, lepidolite and beryl. Slow crystallization from residual, water- and lithium-rich melts allows large, gem-quality spodumene crystals to grow.

Classic gem localities include Pala, California (where it was first described), Afghanistan, Pakistan, Brazil and Madagascar. Pegmatites in these regions yield clean crystals large enough to cut sizable stones.

Spodumene also occurs in massive form in pegmatites mined chiefly for lithium, where the gem-quality kunzite is a rare byproduct.

Look for transparent pink to lilac stones with a vitreous luster, hardness 6.5-7, and very strong pleochroism, colorless to pink to violet depending on viewing direction. The strongest color appears along the crystal length.

Spodumene has perfect prismatic cleavage in two directions and a flat, striated crystal habit, which helps identification but makes cutting and wearing risky. It may show pink fluorescence under UV.

Look-alikes include morganite (pink beryl), pink topaz, rose quartz and pink tourmaline. Kunzite's exceptional pleochroism and perfect cleavage distinguish it; morganite and topaz lack such strong pleochroism, and rose quartz is usually translucent and softer in appearance.

Kunzite is used as a gemstone in pendants, earrings and occasional rings, though its perfect cleavage and brittleness make it better suited to protected settings and gentle wear. Large clean stones are popular because the rough is often sizable.

Because the color can fade with prolonged sunlight exposure, kunzite is sometimes called an "evening stone" and should be stored away from strong light. Spodumene more broadly is a major industrial ore of lithium for batteries and ceramics.

Metaphysically, kunzite is associated with love, emotional healing and the heart, though these claims are not scientific.