Which gemstone is known as the king of gemstones?

The Ruby is known as the king of gemstones because of its deep red colour, rarity, high economic value, and strong historical ...
The New York Times

THE INDUSTRY OF IMITATING PRECIOUS STONES; A Struggle by Science to Compete with Nature and Some of Its Results -- The Story of the Artificial Ruby.

TimesMachine is an exclusive benefit for home delivery and digital subscribers. About the Archive This is a digitized version of an article from The Times’s print archive, before the start of online ...