Svetova E.N., Svetov S.A. Mineralogy and Geochemistry of Agates from Paleoproterozoic Volcanic Rocks of the Karelian Craton, Southeast Fennoscandia (Russia)
https://doi.org/10.3390/min10121106

Agates are unique natural formations, whose beauty and distinctive pattern have drawn people’s attention since old times. They occur in igneous and sedimentary rocks in different parts of the world. The genesis of agates has been an issue discussed by researchers over the past 250 years. However, there is still no definitive and consistent consensus theory of agate genesis yet.
Researchers from KarRC RAS Institute of Geology E.N. Svetova and S.A. Svetov approached the mystery of the formation of these amazing minerals by studying the mineralogical and geochemical features of agates from ancient (2100−1920 Ma) volcanic structures in the Onego catchment.