Ruby comes from the Latin "ruber" meaning red, and they can come in a variety of different shades. Rubies can be anything from a deep rich red to a more pinkish tone. Early records also see rubies called “Ratnaraj” in Sanskrit, meaning “King of Gems”.
Rubies are made of corundum and get their signature red colour from trace amounts of chromium.
Red spinel was assumed to be a ruby until scientists discovered it was a completely different gemstone in the late 18th century! One of the most famous examples of this mistaken identity is the “The Black Prince’s Ruby”, a 170-carat irregular spinel bead that has been in the British Royal Family’s possession since 1367.