Lovely lavender-purple tanzanite is actually a blue zoisite that was renamed by jewelry store Tiffany & Co. as a tribute to where it was first discovered (Tanzania). The semiprecious gemstone closely resembles, and is often confused with, sapphire and iolite. However, it is less lustrous and hard than sapphire, and has lower density and refractivity than iolite. Almost all tanzanites on the market have been heat-treated to produce a deeper color (the rough is brownish yellow). The gemstone displays pronounced pleochroism (different colors at different angles). Handle tanzanite beads with care and protect them from knocks or blows. Do not clean them in an ultrasonic machine or steamer; high temperatures and quick temperature changes can damage them. Tanzanite is believed to help wearers slow down, take it easy, and awaken their hearts and minds. Physically, it is said to help stress-related illnesses, especially high blood pressure.