Umberto Sborgi

Sborgite is a sodium borate mineral with formula Na[B₅O₆(OH)₄]·3H₂O. The formula can be written as the oxide formulation, Na₂O.5B₂O₃.10H₂O. Sometimes called sodium pentaborate pentahydrate it contains the pentaborate anion, (B₅O₆(OH)₄).

Sborgite is colorless with monoclinic crystals. It was named for Umberto Sborgi, (1883–1955), Professor of Chemistry, University of Milan, Italy. Sborgite occurs in Tuscany, Italy and the Furnace Creek district, Death Valley, California, US.