Obsidian, a type of volcanic glass, is formed from rapidly cooling lava. Black obsidian is the most common, but Inclusions of various mineral crystals can give obsidian a brown color, or a rainbow or metallic sheen.
A wide variety of rocks, minerals, and semi-precious gemstones are available for collecting on lands managed by the Bureau of Land Management (BLM). Most BLM lands are open to rock collecting. Collectors should note that there are some restrictions, and a BLM permit may be needed depending on the amount of material you collect, how you collect it, where or when you collect, and whether it is used commercially. Contact your local BLM office for more information.
Note: The excavation, collection or destruction of any human remains, and archaeological or historical materials located on Federal land is illegal and prohibited by Federal and State laws. This includes skeletal materials, arrowheads, flakes, pottery or potsherds, mats, rock art, old bottles, and pieces of equipment or buildings. Any human remains should be left intact and reported to Federal or State authorities immediately. A permit is needed for collecting vertebrate fossils, but not for common invertebrate fossils.