
Calcite CaCO3
Although a rather usual mineral throughout much of Western Ohio, Calcite geodes are a highly uncommon occurrence. Unlike many midwestern states where Quartz geodes are widespread and abundant, geodes of any type are a rare find throughout the state. The Calcite in these geodized brachiopods formed in two or more generations. The first generation of Calcite forms a coating of drusy appearing crystals completely lining the hollow interior of the fossil. While rare doubly terminated crystals are occasionally found, most first generation Calcite crystals are well formed clear white to grayish brown, singly terminated scalenohedrons or scalenohedrons with rhombohedral modifications. Typically, first generation crystals areRead More →