Sublimated iodine and Crosby iodine are chemically identical and can be used in similar applications. The difference is in the physical form of the solid iodine. Crosby iodine is actually solid iodine that has been broken down into smaller pieces. While sublimated iodine is solid iodine that has been obtained directly from iodine vapor. However, sublimated iodine is usually purer and is preferred for applications that require higher purity.