Next week we’ll be reviewing our mineral collections at the Horniman, which means that I’ve been trying to track down the various minerals in the collection. Amongst them I found this rather lovely sample of bismuth – a non-toxic, silvery, heavy metal that can naturally grow into an intricate step-structure crystal.

As the outer surface of the bismuth crystal oxidises it becomes iridescent, creating a beautiful and multifaceted structure that is really quite gorgeous. Hope you like it!