These Moss Agate cabochons are flat back, smooth domed stones. Moss Agate is formed from silicon dioxide, and is a variety of Chaldedony, belonging in the quartz family. Known for the greenish filaments and almost plant-like veining in the stones, there is a wide range of color within each stone and batch. No two are exactly the same. The shades range from a light grey to dark forest green. Each stone is a hand worked lapidary item, so natural variation in materials, cut and sizing may occur.