 Boric acid, or sassolite, is found mainly in its free state in some volcanic districts, for example, in the Italian region of Tuscany, the Lipari Islands and the US state of Nevada.In these volcanic settings it issues, mixed with steam, from fissures in the ground.It is also found as a constituent of many naturally occurring minerals – borax, boracite, ulexite (boronatrocalcite) and colemanite.