This lovely Moss Agate Necklace is a great example of the Scottish Popular Gem Stone, Moss Agate is a semiprecious stone. Formed from Silicon Diode. Despite it's name it does not contain any organic matter. It is always interesting to see the formations of grass and trees and lines in the gem stone. The necklace is marked sterling in the gem holder and on the chain spring closure. The way the chain is fasten to the gemstone frame it would not slide on the chain. A touch of Scotland Beautiful!