Gilsonite

It is used in construction, Pharmateucical and other industries
Gilsonite or  Asphaltum , Natural asphalt is similar to a hard petroleum asphalt and is often called a natural asphalt, asphaltite, uintaite, or asphaltum.  Gilsonite is soluble in aromatic and aliphatic solvents, as well as petroleum asphalt. Due to its unique compatibility, Gilsonite is frequently used to harden softer petroleum products. Gilsonite in mass is a shiny, black substance similar in appearance to the mineral obsidian. It is brittle and can be easily crushed into a dark brown powder. Gilsonite is found below the earth's surface in vertical veins or seams that are generally between two and six feet in width. The veins are nearly parallel to each other and are oriented in a northwest to southeast direction. The vein will show up on the surface as a thin outcropping and gradually widen as it goes deeper.  Due to the narrow mining face, Gilsonite is mined today, much like it was 50 or 100 years ago.  The primary difference is that modern miners use pneumatic chipping hammers and mechanical hoists .