Spinel is a gemstone that at one time was most famous for being mistaken for ruby or sapphire. These days spinel gets the respect it deserves–– it is recognized for its excellent hardness (8 on the Mohs scale) and brilliance. 2 3/4 carats total weight (20) lab-created Blue spinel (1)4.5mm roundlab-created DiamondAura, 5/8ctw (center stone) (46)1mm round lab-createdDiamondAura accents .925 sterling silver setting