Gilsonite

Asphaltite (also known as uintahite, asphaltum or gilsonite) 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 Uintah 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.[2] Gilsonite 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.