This sample of poudrettite is displayed in the Smithsonian Museum of Natural History. Poudrettite is a silicate mineral that contains boron as well as potassium and sodium It has the composition KNa2BSi12O30. The gem sample at left is 9.41 carats and is from Burma.
The spelling poudretteite is also used, and is used by Mindat. This is a rare mineral.