HISTORY, NAME, LOCALITIES: The name “agatized coral” alludes to its origin, in which chalcedony (microcrystalline quartz) has replaced coral. Agatized quartz’s few important collecting localities include Florida and West Virginia.
MINERALOGY, PROPERTIES, OCCURRENCE: The physical properties of agatized quartz are the same as those of chalcedony [microcrystalline quartz, silicon dioxide, SiO2]. It has a Mohs hardness of nearly 7.0, a conchoidal fracture, a waxy luster, and a specific gravity of 2.65. Its colors include blacks, browns, grays, yellows, and reds. Agatized quartz forms when silica replaces the aragonite and organic materials in coral after it has been buried. It often has a somewhat geodic structure and polychrome colors. Many specimens also have dusy coatings of colorless, macrocrystalline quartz crystals. Agatized coral retains some of the cellular and surface features of the original coral. It is recovered from weathered limestone and other sedimentary rocks.
METAPHYSICAL PROPERTIES, LORE, USES: Metaphysical practitioners believe that agatized coral has unusually high energy because it combines the energies of coral and quartz. It is thought to increase general awareness of life’s interactions, helps to recall memories, and provide the willingness to accept others and meet life with a giving heart. Native Americans of Florida utilized agatized coral extensively to manufacture tools and weapons. In 1979, agatized coral was officially named the state stone of Florida.
COLLECTORS’ INFORMATION: Today, agatized coral is widely collected for its many colors and fossil-coral features. It is cut and polished to make display pieces, and is also fashioned into cabochons for pendants.