Most look like a real rose that has been fossilized. Nice specimens from Oklahoma. Click here to learn more about the Barite Rose. M725 Bismuth Crystals Natural bismuth crystals are extremely rare. These were grown in a laboratory in Florida.
Bismuth forms fascinating patterns when it crystallizes and is heavier than lead.
The crystals vary in color and have an iridescent sheen. Chemical impurities such as iron, manganese, magnesium, zinc or cobalt cause calcite to be many different colors. Calcite is polymorphic to aragonite. They both contain the same elements but have a different crystal structure, which was caused by different environmental conditions when the crystallization took place. Stalagmites and stalactites are formed from calcium-rich ground water seeping through caves.