Labradorite is a mineral which can display an iridescent effect in which it shimmers in the presence of light. This beautiful and dazzling optical phenomenon is known as labradorescence. Labradorite was identified in Labrador, Canada, hence its name. The mesmerizing color of this stone resembles the northern lights. The stone comes in many shades of black and brown, but many varieties may come in gray, brown, green, blue or yellow.