asphaltite

thumb|Asphaltite from the Uinta Formation, Bonanza, Utah|Bonanza, [[Utah]] thumb|Asphaltite pahoehoe paralava. This remarkable specimen is from asphaltite which was melted in a wildfire in 2012. While molten, it developed a smooth to ropey top surface much like pahoehoe basalt lava. Exhibit at the [[Utah Field House of Natural History.]] Asphaltite (also known as uintahite, asphaltum, gilsonite or oil sands) is a naturally occurring soluble solid hydrocarbon, a form of asphalt (or bitumen) with a relatively high melting temperature. Its large-scale production occurs in the Uinta Basin of Utah and Colorado, United States.

Although the substance has been historically mined in the Uintah Basin, resources are being discovered and mined more recently in other countries such as Colombia and Iran. Asphaltite is mined in underground shafts and resembles shiny black obsidian. Discovered in the 1860s, it was first marketed as a lacquer, electrical insulator, and waterproofing compound approximately 25 years later by Samuel H. Gilson.