Rainbow Hematite is a man-made crystal that forms when Titanium is vaporized and fused with Hematite to give it that oil-slick luster. This doesn't mean it serves no purpose, simply that it's vibrations have changed. It dissolves negative energy and can help a person feel grounded. Rainbow Hematite is great to meditate with as it works to calm the mind, promotes inner peace, raising consciousness and vibrations.
Tumbled stones have been smoothed or polished from their raw form, not into any specific shape but are no longer rough or jagged to the touch. These crystals are usually more affordable and are good for everyday crystal use such as grids, meditation, affirmations, altar work, feng shui and more.