Alaska -- The State has several varieties of chalcedony found at different locations, including agates, jaspers, and petrified wood. Various types of agates can be found in gravel pits and gravels of stream and river beds at several locations in the Chicken Creek area near the border with the Yukon Territory.
more about rockhounding in Alaska
Arizona -- Arizona is well known for its petrified wood because of the Petrified Forest National Park, and petrified wood ranks third in value of commercially produced gemstones. It is generally accepted that the Park contains the most colorful examples of silicified logs in the world.
more about rockhounding in Arizona
California -- California's "Mojave Blue" agate has gained a great deal of attention in the past several years. This pastel blue or blue-gray agate cuts into attractive cabochons for jewelry and, in the hands of an expert carver, makes outstanding carvings.
Colorado and Utah -- These States have deposits of fine quality jasper, agate, petrified wood, and agatized dinosaur bone. These deposits are found over a large area of both States and on both sides of the continental divide in Colorado.
Florida -- The famous silicified coral, first found in the Tampa Bay area around 1825 is the only gemstone of note from the State. Since its discovery in Tampa Bay, the agatized coral also has been found at Tarpon Springs, south of New Port Richey, near the town of Kathleen, and along the banks of the Suwanee River in Hamilton, Columbia, and Suwanee Counties. The material is found...
more about rockhounding in Florida
Idaho -- Jasper mining was beginning to make a comeback in the State, particularly with the operation of the Willow Creek jasper mine when in 1992, the untimely death of one of the partners mining the property, resulted in jasper mining reverting to hobbyist and professional collectors. Production of the various jaspers should be adequate to meet demand for the foreseeable future.
Montana -- Montana moss Agate is the grayish-white to gray translucent chalcedony containing dendrites. The black, brown, or red tree-like or scenic dendritic growths are actually included minerals of manganese and iron. Most of the moss agate is found as water worn cobbles in the Yellowstone River or its drainages between Billings and Sidney. The material can be collected in Yellowstone, Treasure, Rosebud, Custer, Prairie, Dawson, and Richland Counties. The agate has long been a favorite of hobbyist and professional cutters because of the beautiful and highly variable patterns, the durability, and ease in cutting and polishing.
New Mexico -- Varieties of agate, jasper, chert, or petrified wood are found in 15 of New Mexico's 32 counties. An area of about 100 hectares near Deming, New Mexico Rockhound State Park, is set aside for the non-commercial collecting of agate, jasper, and petrified wood.
Oregon -- The State is known for the production of various picture and scenic jaspers, agates, thundereggs, and petrified wood. Graveyard Point, Priday, and Polka Dot are names that are familiar to most agate collectors rockhounds, and many lapidaries. These are also...
more about rockhounding in Oregon
South Dakota -- The State's best known chalcedony is its colorful and beautiful Fairburn agates. Named after a community near a very prolific agate deposit in Custer County, these brightly colored banded agates are similar to Lake Superior agates found in Michigan and Dryhead agates from Montana. The color patterns are ...
more about rockhounding in South Dakota
Tennessee -- Agates can be collected from many different locations and geological formations across the State. The material includes golden tone agate from Hawkins Co., agatized oolites from Greene Co., carnelian, blue, ivory, pink, finely banded, dendritic, moss, iris and Fairburn style agate from Bedford Co., and Lake Superior type agate and agatized corals and sponges from Shelby Co. All of the material is suitable for cutting and takes a good polish.
Texas -- Some of the best agate, jasper, chert, and petrified wood (particularly petrified palm wood) found in the nation comes from Texas. Blue banded, moss, and red and black plume agates are found near Alpine in Brewster County. Similar agates are found in Jeff Davis, Hidalgo, Hudspeth, Presidio, Reeves, San Patrico, and Starr Counties. Petrified wood can be found...
more about rockhounding in Texas
Washington -- Washington' s petrified woods are some of the finest in the nation. The woods not only represent a broad range of colors and patterns, but also represent a wide range of identifiable species. Species identified include redwood, oak (more than 10 varieties), cypress, elm, maple, willow, cedar, poplar, chestnut, alder, birch, persimmon, laurel, and ginkgo. The preserved woods have been used to make cabochons, table tops, pen bases, and other objects of art.
Deposits in the State also furnish a selection of agates that include moss, blue, and carnelian. The blue agate from Kittitas County, known as Ellensburg Blue, is highly prized by local lapidaries.
Wyoming -- Wyoming's claim to fame is its fine-quality agates and petrified wood. Deposits across the State supply a variety of seam, moss, banded, fortification, and turritella agates. Colorful and attractive specimens of petrified wood can be found in many areas in the State.
Others -- This is by no means a complete summary of chalcedony production in the United States. Flint from Flint Ridge, OH, and Lake Superior Agate from the Great Lakes were not discussed, nor was many other agates or jaspers from individuals favorite collecting locations. But in the space available, the better known or commercial producing locations were mentioned.