Blue Amber 13mm Bead Bracelet Straight Limited EditionIt is cheap because the amount of color is small. This is blue amber, which is said to be extremely rare among amber. The reason why blue amber is rare is because it emits a special color when exposed to ultraviolet light. Normally, these beads have a golden color, but they react to even the slightest amount of ultraviolet light and turn a vivid blue depending on the angle. You can especially notice the change in color when you place them on a black