Product Overview
Greywacke or graywacke is a sedimentary rock composed of large, angular clasts within a fine-grained clay matrix. Formed during underwater avalanches, these rocks are often found on distal ocean shelves. Useful when digging deeply into sedimentary petrology and classification, graywacke can also be used in general identification exercises. While each specimen will vary slightly in shape, size and color, it will measure approximately 3" in length. Each is individually packaged, labeled & barcoded for easy identification and storage.
