Although jewelry plays a very small role in Grand Theft Auto IV, it is possible to acquire some pieces throughout the course of the game. The most common way to get jewelry is to simply find it lying around on the ground or in abandoned vehicles. However, there are a few specific missions and side-quests that will also net you some nice bling.
One mission that will award you with jewelry is “ Diamonds Are a Girl’s Best Friend ”, given to you by Gracie Ancelotti. During this mission, you must help Gracie retrieve her stolen diamonds from a group of thugs. Upon completion of the mission, Gracie will give you a diamond necklace as thanks.
There is also a chance to earn some jewelry during the random event “Jewelry Store Heist”. In this event, four men will attempt to rob a nearby jeweler at gunpoint. If you intervene and stop the robbery, the jeweler will offer you a reward – which can include anything from cash to diamond rings.
Finally, if you happen to have acquired enough money through other means (such as completing missions or selling drugs), you can always just purchase your own jewelry outright from any one of Liberty City’s many fine jewelers!