Calcite, Aragonite and Dolomite (variety ferroan) on Quartz - Keokuk, USA - geode is about 3.3 cm, calcite is 0.7 cm, aragonite spray is 1.3 cm

Mineral: Calcite, Aragonite and Dolomite (variety ferroan) on Quartz
Locality: Keokuk, Lee County, Iowa, USA
Dimensions: geode is about 3.3 cm, calcite is 0.7 cm, aragonite spray is 1.3 cm

Description: calcite, aragonite and decayed ferroan dolomite on quartzThe so called "blue quartz" variety with calcite adjacent to an aragonite spray. This is unusual