A jewellery box is read as a store of what you value most — memories, gifts, secret hopes. Opening one in a dream traditionally stands for rediscovering worth you had put away.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.