Price is for one tumbled stone. Hackmanite is tenebrescent, meaning it fluoresces under ultraviolet light and it changes color when brought into the sunlight from darkness. When in the dark, Hackmanite will appear a purple color and when in the sunlight it turns a light beige to nearly a white color. When under UV light, Hackmanite will fluoresce a neon orange color. If you choose to purchase a Hackmanite tumble, one will be intuitively chosen for you.