Yes, you can store your crystals together without issue. But if you’re storing many small crystals together, you should individually wrap them, so they don’t chip and crack. You can group crystals based on their form if you don’t want to wrap them. For example, you can keep tumbled crystals together because of their durable finish.
While crystal storage is a personal choice, you should still be aware that there are optimal ways to store them. Since crystals attract and absorb negative energies, it’s best to find ways to minimize their exposure to outside energies.