Bitumen, Natural Asphalt, Asphaltites & Asphaltic Rocks

Gilsonite (uintaite) is a naturally occurring solid hydrocarbon asphaltite mined primarily in Utah and imported in smaller quantities. Unlike lake asphalt or asphaltic rock, gilsonite is nearly pure bitumen with very low mineral content, giving it unique solubility and binding properties valued in oil-well cement, printing inks, and asphalt modification. Its high purity distinguishes it from asphaltic rocks, which contain significant mineral matrix material.

A geological origin certificate or supplier declaration confirming the material is mined from a natural deposit — rather than produced as a refinery residue — is the primary supporting document. Laboratory analysis showing the absence of refinery processing markers (such as specific aromatic compound profiles) can further support the classification. CBP may request this documentation during examination, particularly for materials like natural lake asphalt that visually resemble petroleum bitumen.