Considering that it's a chemical element that's been around since ancient times the fact that bismuth is still able to amaze is testimony to just how incredible it is. One of the first 10 metals to ever be discovered the name bismuth started appearing in texts around 1660 although the element was first confused with tin or lead for its similar looking raw state.
There's certainly no mistaking bismuth crystals however, thanks to their unique rainbow like appearance, although they can only be created under the right conditions. Incredibly rare to find in nature the iridescent crystals you see below are more commonly fabricated in a lab. Thanks to its low melting point at just above 271 °C (520 °F), the transformation of the crystal happens when it's in liquid form, turning into the iridescent rainbow stairways you see below.
Even cooler is that you can make these bismuth crystals yourself and there are plenty of DIY guide's on how to do so online.