If you are looking for a specific type, make sure that the normal item matches the type of the unique one you want. You must use the Orb of Chance on a white-rarity (affixless) Sapphire Ring.

It also has an 18K yellow gold band. This gorgeous cluster ring features three unique pink Fair Trade Montana Sapphires set in 18k yellow gold. Each ring will come with three unique stones ...

By trading with other players. Dream Fragments Sapphire Ring is a random drop unique that has the possibility of dropping from Level 12+ monsters, which means it can be obtained as early as Act 1 ...