When the crystal is exposed to the air and cooled, the color of the natural rainbow will be produced, and then the luminous rainbow color of the rainbow will be produced, as you can see in the pyramid structure. Aurora crystal is a perfect natural raw mineral. Its energy is several that of standard chakra stone. It provides powerful energy and spiritual power for chakra, , meditation, vitality, wisdom, love and dedication, balances emotions, calms anxiety and increases creativity. Natural rainbow colors develop as the crystal is exposed to air and cools that then create the luminescent colors of the rainbow that you see in the pyramid structure. The natural bismuth crystals are also very suitable for specimen collection, decoration, jewelry making and gifts. Properly package, protect and buffer to prevent damage. However, it should be that bismuth crystals are fragile, so if they fall, they may break into many pieces, but they are still beautiful and unique pieces. Bismuth may have sharp edges and should be handled with care. Material: Bismuth crystal colour: Multicolor Package Contents: 1 x bismuth crystals(50-60 Grams) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.