Gilsonite or Natural Bitumen by Monamorco is also known as Natural Asphalt, Asphalting, and is soluble in petroleum asphalt solvents. Gilsonite is used in the hardening of oil products and it is easily converted to powder form.Gilsonite Natural Asphalt , Natural Bitumen , Hard Asphalt or Hard Asphaltum is used as a performance-enhancing agent for asphalt mixes. Gilsonite-modified paving mixes achieve higher PG grades and incorporate perfectly into the asphalt blend with no need for high shear milling as is the case with many other modifiers.