Science, Tech, Math › Science State Gemstones of the United States Share Flipboard Email Print Don Farrall/Getty Images Science Geology Types Of Rocks Landforms and Geologic Features Geologic Processes Plate Tectonics Chemistry Biology Physics Astronomy Weather & Climate By Andrew Alden Geology Expert B.A., Earth Sciences, University of New Hampshire Andrew Alden is a geologist based in Oakland, California. He works as a research guide for the U.S. Geological Survey. our editorial process Andrew Alden Updated November 01, 2017 Thirty-five of the 50 states have designated an official gem or gemstone. Some states like Missouri have named an official state mineral or rock, but not a gemstone. Montana and Nevada, on the other hand, have chosen both a precious and semiprecious gemstone. Although the laws may call them "gems," these state gemstones are generally not sparkling crystals, so it is still more accurate to call them gemstones. The majority are colorful rocks that look their best as flat, polished cabochons, perhaps in a bolo tie or belt buckle. They are unpretentious, inexpensive stones with democratic appeal. 01 of 27 Agate Julie Falk/Flickr Agate is the state gem of Louisiana, Maryland, Minnesota, Montana, Nebraska, and North Dakota. This makes it by far the most popular state gemstone (and state rock). 02 of 27 Almandine Garnet State Gemstones of the United States. Dave Merrill/Flickr Almandine garnet is the state gem of New York. The world's largest garnet mine is in New York, but it produces the stone exclusively for the abrasives market. 03 of 27 Amethyst Andrew Alden/Flickr Amethyst, or purple quartz crystal, is the state gem of South Carolina. 04 of 27 Aquamarine Andrew Alden/Flickr Aquamarine is the state gem of Colorado. Aquamarine is the blue variety of the mineral beryl and is typically found in block-shaped hexagonal prisms, which are the shape of pencils. 05 of 27 Benitoite State Gemstones of the United States. Photo (c) 2004 Andrew Alden, licensed to About.com ( fair use policy) Benitoite is the state gem of California. In all the world, this sky-blue ring silicate is produced only from the Idria locality in the central Coast Range. 06 of 27 Black Coral State Gemstones of the United States. Gordana Adamovic-Mladenovic/Flickr Black coral is the state gem of Hawaii. Various species of black coral occur around the world, and all of them rare and endangered. This specimen is located in the Caribbean. 07 of 27 Blue Quartz Jessica Ball/Flickr Star blue quartz is the state gem of Alabama. Blue quartz like this contains microscopic inclusions of amphibole minerals and occasionally exhibits asterism. 08 of 27 Chlorastrolite Charles Dawley/Flickr Chlorastrolite, a variety of pumpellyite, is the state gem of Michigan. The name means "green star stone," after the radiating habit of the pumpellyite crystals. 09 of 27 Diamond Andrew Alden/Flickr Diamond is the state gem of Arkansas, the only state in America with a diamond deposit open for public digging. When they are found there, most diamonds look like this. 10 of 27 Emerald Orbital Joe/Flickr Emerald, the green variety of beryl, is the state gem of North Carolina. Emerald is found as stubby hexagonal prisms or as streamworn pebbles. 11 of 27 Fire Opal Andrew Alden/Flickr Fire opal is the state precious gem of Nevada (turquoise is its state semiprecious gem). Unlike this rainbow opal, it displays warm colors. 12 of 27 Flint Andrew Alden/Flickr Flint is the state gem of Ohio. Flint is a hard, fairly pure type of chert used by Indians for toolmaking and, like agate, attractive in polished cabochon form. 13 of 27 Fossil Coral David Phillips/Flickr The fossil coral Lithostrotionella is the state gem of West Virginia. Its growth patterns combine with the attractive colors of agate in a desirable gemstone. 14 of 27 Freshwater Pearls Helmetti/Flickr Freshwater pearls are the state gem of Kentucky and Tennessee. Unlike sea pearls, freshwater pearls have an irregular form and a wide range of color. Pearls are considered a mineraloid. 15 of 27 Grossular Garnet Bryant Olsen/Flickr Grossular garnet is the state gem of Vermont. This garnet mineral ranges in color from green to red, including golden and brownish colors as seen in this specimen. 16 of 27 Jade Adrià Martin/Flickr Jade, specifically nephrite (cryptocrystalline actinolite), is the state gem of Alaska and Wyoming. Jadeite, the other jade mineral, is not found in useful quantities in the United States. 17 of 27 Moonstone Dauvit Alexander/Flickr Moonstone (opalescent feldspar) is the state gem of Florida, although it does not naturally occur there. The state cited moonstone to honor its space industry. 18 of 27 Petrified Wood tree-species/Flickr Petrified wood is the state gem of Washington. Agatized fossil wood makes attractive cabochon jewelry. This specimen was found at Gingko Petrified Forest State Park. 19 of 27 Quartz Andrew Alden/Flickr Quartz is the state gem of Georgia. Clear quartz is the material making up Swarovski crystals. 20 of 27 Rhodonite Chris Ralph/Wikipedia Rhodonite, a pyroxenoid mineral with the formula (Mn,Fe,Mg,Ca)SiO3, is the state gem of Massachusetts. It's also known as manganese spar. 21 of 27 Sapphire Beth Flaherty/Flickr Sapphire, or blue corundum, is the state gem of Montana. This is an assortment of stones from Montana's sapphire mines. 22 of 27 Smoky Quartz Andy Coburn/Flickr Smoky quartz is the state gem of New Hampshire. 23 of 27 Star Garnet Claire H/Flickr Star garnet is the state gem of Idaho. Thousands of needlelike mineral inclusions create a starlike pattern (asterism) when the stone is cut properly. 24 of 27 Sunstone Paula Watts Sunstone is the state gem of Oregon. Sunstone is feldspar that glitters from microscopic crystals. Oregon sunstone is unique in that the crystals are copper. 25 of 27 Topaz Andrew Alden/Flickr Topaz is the state gem of Texas and Utah. 26 of 27 Tourmaline Orbital Joe/Flickr Tourmaline is the state gem of Maine. Many gemstone mines are active in Maine's pegmatites, which are deep-seated igneous rocks with large and rare minerals. 27 of 27 Turquoise Bryant Olsen/Flickr Turquoise is the state gem of Arizona, Nevada and New Mexico. There it is a prominent aspect of Native American culture.