It states (Shemos 35:27), אבני את הביאו והנשיאים ולחשן לאפוד המלואים אבני ואת השהם, "The nesi'im brought the shoham stones and the [filling] stones for the eifod and the choshen." Where did the nesi'im obtain these precious gems? Did they own them?
Targum Yonason writes, "The clouds of glory went to Pishon and picked up precious stones...to be placed in the eifod and choshen."