Chipped cup

The chipped cup was a part of Rumplestiltskin's tea set that, when she was cleaning, Belle dropped and chipped. After he lost Belle, the cup became more and more treasured to Rumple and he rendered it his most cherished keepsake.

Before the Curse
Rumplestiltskin is running by Belle her list of chores as she pours him his tea, he tells her that she will be skinning the children he hunts and a shocked Belle drops the tea cup in her hand on the floor, he tells her that the last chore was a quip. Belle goes to pick up the cup but it is chipped, she tries to assure Rumple that it can hardly be seen by he tells her that it's just a cup. As time goes on, Rumple falls in love with Belle but refuses to believe that she loves him, he becomes enraged and locks her up. In his anger, he smashes his tea set against the wall, except for one item: Belle's chipped cup. Later, Rumple lets Belle go and Regina later visits him, she explains that Belle was shunned after knowing him and through herself from the battlements (it is later revealed she's lying) so, when the queen leaves, Rumple removes a trophy from a podium and places the chipped cup there instead, it now meaning more to him than any other object.

Season 1
When Mr. Gold repossesses Moe French's truck, Mr. French retaliates by robbing Gold. Emma is alerted to the situation and manages to retrieve all of the items in less than a day, however, one particular item is missing, and until it is retrieved, Mr. Gold tells her that she might as well have recovered nothing. Hell-bent on getting his item back, Mr. Gold ties up and gags Moe and throws him into the back of his van, he takes him to a cbin in the woods and begins to beat the poor man until he tells him where the item is and who told him to take it. Gold is caught by Emma and arrested, and, in his cell, he is visited by Regina. Regina says that she has his item and will give it to him in exchange for his name, Gold says that his name is Rumplestiltskin and Regina gives his precious item back: his chipped cup. As Regina leaves, Gold stares at his cup in his cell, relieved to have it back.

Season 2
When Belle returns to Rumplestiltskin after leaving in a rage, she sees that in his shop, there is her chipped cup. She is happy that he kept it all those years and he assures her that that cup has meant more to him than anything for all the years that they'd been apart. Belle is touched.