Perhaps the best known spinel to have been misidentified as ruby is called “the Black Prince's Ruby,” part of the British Imperial State Crown. This magnificent 170-carat red spinel was worn by Henry V of England in battle!

What gem is most mistaken for ruby?

Spinel was recently added as an August birthstone, sharing this month with peridot and sardonyx. It has long been mistaken for ruby by emperors and monarchs. Many of the famous “rubies” of history were actually spinels.

How can you tell a ruby from spinel?

A ruby is dichroic (meaning it shows different colours when viewed from different directions) whereas a spinel is singly refractive (it has only one refractive index - much like diamond and garnets), this property means that spinels general have vivid fire and colour, making it a wonderful stone to work with on ...