Alchemical Planetary Bodies
The goal of ancient alchemy was to transform something of little value, like lead, into something of considerable value, like gold, using a device known as the Philosopher's Stone. Although they were unaware of it at the time, such theory is not unscientific. When it first began, the universe was merely hydrogen. Element transformation is possible during fusion. More nuclei are added to molecules, and hydrogen turns into helium. That occurs daily in our sun.
Stars can produce elements heavier than iron, such as gold and platinum, in a process akin to a supernova. All of these elements were created by the fundamental forces of the cosmos, and as a result, over the course of millions and billions of years, entire planets have evolved that are nearly exclusively composed of single elements or fundamental compounds.
Scientists found an iron planet in 2021, while a diamond-made world made headlines in 2012. The planet Gj 1214b is largely made of water. Not to be outdone, scientists also found an asteroid named Psyche 16 that contained platinum and gold valued over $10,000 quadrillion.