What Is Labradorite? The Physics Behind Its Flash

Labradorite is a feldspar mineral, first described near Labrador, Canada. Its signature flash of color — called labradorescence — comes from a different optical mechanism than moonstone's glow: light entering the stone hits thin, stacked internal layers (formed by a structural quirk called lamellar twinning) and interferes with itself, similar to how a soap bubble or a thin film of oil on water splits light into distinct colors.

This is why labradorite's flash appears as specific, sharp colors that shift abruptly as the stone is tilted, rather than the soft, floating glow of moonstone. The most vivid material — sometimes called spectrolite — comes from Finland, with other significant deposits in Madagascar.