Identification: Common clay is a sticky, plastic type of sedimentary rock that is composed primarily of varying amounts of clay minerals, quartz sand, calcite, iron oxides, organic impurities and other materials. Most of the clay in Florida was originally deposited as a mud in seas, lakes, rivers, or on deltas. Clay may occur in a wide variety of colors depending upon its mineralogical composition, impurities, and the amount of weathering which it has undergone.

Occurrence: Common clay occurs in almost every county north of the latitude of Lake Okeechobee.

Production and Use: The principal use of common clay in Florida is as an addition to sand in the construction of roads. Florida clays are also used in the manufacture of Portland cement and lightweight aggregate.