These crystals are typically formed by slowly cooling molten bismuth, which causes it to solidify into these unique, colorful structures. The colors seen in bismuth crystals—ranging from pinks and purples to blues and greens—are due to interference effects of light interacting with the oxide layer.
Bismuth crystals are not only visually captivating but also have interesting properties. They are diamagnetic, meaning they repel magnetic fields, and their low thermal conductivity makes them useful in specific applications. Because of their striking appearance, bismuth crystals are often used as decorative pieces and in artistic displays.