West Virginia Symbols, Gemstone: Fossil Coral

Adopted on March 10, 1990

The State Gem, so designated by House Concurrent Resolution No. 39, March 10, 1990, is technically not a gemstone, but rather the silicified Mississippian fossil coral Lithostrotionella, preserved as the siliceous mineral chalcedony. It is found in the Hillsdale Limestone in portions of Greenbrier and Pocahontas counties and is often cut and polished for jewelry and for display

This coral and many other varieties lived about 340 million years ago, during the Mississippian Period, at a time when the state was encroached on by a shallow sea. In addition to corals, this sea hosted a teeming fauna of brachiopods, trilobites, and fish.

When the coral died, it became saturated with water which contained a dissolved mineral called silica. The silica replaced the coral's decaying soft parts. In other words, the coral became silicified or mineralized. Cavities in the coral were filled with chalcedony—a variety of quartz. But it still looks like coral.

The two main types of Paleozoic corals were tabulate and rugose corals. Lithostrotionella is a tabulate coral. Both types were decimated in the great extinction at the end of the Permian Period, 245 million years ago, which wiped out over 90% of the species of life on earth. They were subsequently replaced by the scleractinian corals which form our reefs today.

Corals may look like plants, but they are really animals. The familiar part of a coral is a colony's calcium carbonate skeleton; in each small recess lives an individual coral animal called a polyp. These polyps strain small particles of food from the water with their tentacles, and retreat into the safety of the skeleton when threatened. Additionally, the polyps host symbiotic algae called zooxanthellae within their tissues, which are nourished by the coral's waste products and in turn provide additional food via photosynthesis. These algae give the corals various colors when they are alive. In fossil form, it is impurities within the minerals that impart various hues. Many West Virginia coral reefs have been replaced by chalcedony, a variety of microcrystalline quartz.

Lithostrotionella is found almost exclusively in the Hillsdale Limestone of Greenbrier and Pocahontas counties in the southeastern portion of the state.

West Virginia Fossil Coral comes in several colors, including light to dark blue grey, pink, and red.