A coral’s age is measured much the same way as a tree’s…by its growth rings. Researchers have discovered a type of Black Coral that is over 4,200 years old—which means it was alive when the pyramids were being built in ancient Egypt.
"Black corals in the genus Leiopathes are now known to be the longest-living corals in the world.”
Photo by: Bernard DUPONT from FRANCE, CC BY-SA 2.0
https://commons.wikimedia.org/wiki/File:Black\_Coral\_(Antipathes\_sp.)\_(6132712705).jpg
https://www.cbsnews.com/news/black-coral-can-live-for-over-4000-years-leiopathes-annosa/