Danburite is a mineral of the mineral class "silicates and germanates", with a hardness of 7 Mohs scale. It was first found in Danbury (hence its name), Connecticut, USA. Danburit is little known as a gem, but its popularity is growing. Its crystals have excellent purity and are thus very attractive for jewelry use. Danburite is most commonly found in clear, perfectly transparent crystals, but may be colored to light pink, greenish, white, gray or yellow, depending on the presence of other impurities.