In 2017, an international research team of astronomers discovered what may be a planet made of solid diamond.
Pulsars are tiny, dead neutron stars that are only around 12.4 miles (20 kilometers) in diameter and spin hundreds of times a second while emitting beams of radiation.
This planet is paired with pulsar PSR J1719-1438 and scientists think it is entirely made of carbon so dense that it must be crystalline, meaning a large part of the world would be diamond. Incredibly, the planet "orbits its star every two hours and 10 minutes, has slightly more mass than Jupiter but is 20 times as dense," according to Reuters.