Bismuth crystals

As our walk round Ferry Meadows yielded nothing of any great photographic merit, I had a quick hunt round the house for something tiny to photograph. These (slightly dusty) man-made bismuth crystals were close to hand, and the colours and structure are rather gorgeous. I can't remember where we acquired them - when the boys were young almost every trip to a museum ended up with the purchase of some minerals or model animals!

Here's some information about bismuth crystals.

"Bismuth in its elemental form is a rare occurrence in nature, even more so for bismuth crystals. Lab grown crystals are popular because of their intricate shapes and dazzling colors. These lab grown crystals form incredible geometric patterns in a stair step arrangement similar to a stadium. The unusual crystal patterns are due the the crystal edges growing at different rates than the crystal faces. They often have several iridescent metallic colors caused by light scattering at a very thin layer of bismuth oxide. Reds, yellows, blues, greens, and purples are common. This is a man made crystal grown in a lab at about 271 degrees centigrade or 520 degrees Fahrenheit. It can only be grown from electronic grade highly refined bismuth."