Though bismuth may be found naturally, the specimens included in this piece were man-cultured. Natural bismuth does not commonly form into crystals nor in its pure form. Rather, its compounds are found with ores of other metals. Man-cultured bismuth crystals are made by melting pure bismuth metal and allowing it to cool. As the metal cools, outer edges of the crystal grow faster than inner edges, resulting in cubic, step-like formations. The iridescent appearance of the crystals can be attributed to variations in the thickness of the oxide layer surrounding the mineral.

​