English: Mosagaat.
Chemical: silicon dioxide.
MineralogyMoss agate is a form of chalcedony which includes minerals of a green color embedded in the stone, forming filaments and other patterns suggestive of moss.
The field is a clear or milky-white quartz, and the included minerals are mainly oxides of manganese or iron. It is not a true form of agate, because it does not have concentric banding.