The Timur Ruby is an unfaceted, 352.54-carat (71 g) polished red spinel set in a necklace. It is named after the ruler Timur, founder of the Timurid Empire and purportedly one of its former owners. It was believed to be a ruby until 1851.

Spinel is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4 in the cubic crystal system. Its name comes from the Latin word spinella, a diminutive form of spine, in reference to its pointed crystals.