Black Agates from Paleoproterozoic Pillow Lavas (Onega Basin, Karelian Craton, NW Russia): Mineralogy and Proposed Origin

• Published in: Minerals
• Main Authors: Evgeniya N. Svetova, Svetlana Y. Chazhengina, Alexandra V. Stepanova, Sergei A. Svetov
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2021
• Subjects: agate; Raman spectroscopy; X-ray powder diffraction; electron scanning microscopy; Paleoproterozoic volcanics; carbonaceous matter; Mineralogy; QE351-399.2; Onega; Fennoscandian; karelia*; karelian
• Online Access: https://doi.org/10.3390/min11090918; https://doaj.org/article/11cd288f1b7042ce808567a5ad0bb25c

The present study provides the first detailed investigation of black agates occurring in volcanic rocks of the Zaonega Formation within the Onega Basin (Karelian Craton, Fennoscandian Shield). Three characteristic texture types of black agates were identified: monocentric concentrically zoning agate...