[[Arbor Philosophorum Perfecta|Diana's Tree]], also known as the [[Arbor Philosophorum Perfecta|Philosopher's Tree]], was considered a precursor to the philosopher's stone and resembled coral in regards to its structure. It is a dendritic amalgam of crystallized silver, obtained from mercury in a solution of silver nitrate; so-called by the alchemists, among whom "Diana" stood for silver. The arborescence of this amalgam, which even included fruit-like forms on its branches, led pre-modern chemical philosophers to theorize the existence of life in the kingdom of minerals.