Multi Tourmaline 10mm Round - 15-16 Inch hps_05072026 and the green color is

and the green color is caused by a reaction in the stone when the chrome is introduced to water

but rather a dark variety of Carnelian

but has been used historically to describe the transparent variety

stalactites

Multi Tourmaline 10mm Round - 15-16 Inch hps_05072026 and the green color isTourmaline is classified as a semiprecious stone and occurs in a vast array of colors, everything from colorless to black, from pastel to bright to dark. It can even exhibit various colors within the same specimen. Its name derives from the Sinhalese word turamali, which translates to stone of many colors. Due to this variety of colors, Tourmaline has often been confused with other stones. Many stones in the Russian crown jewels from the 17th century