DESCRIPTION: A Concretion is a compact mass of precipitated minerals which is commonly spherical to discoid in overall shape and is found embedded within a host rock which is common;y of a different composition.
Figure 1 - Large Concretion growing within fine sediments. These large nodules found in northwest NY State near the Great Lakes shore are commonly Septarian in nature.
Figure 2 - Large Concretion growing within fine sediments as for Figure 1. In the background is a Tillite