Povondraite is a rare silicate mineral from the tourmaline group with formula: NaFe³⁺₃(Fe³⁺₄,Mg₂)(BO₃)₃Si₆O₁₈(OH)₃O. It is a dark brown to black nearly opaque mineral with a resinous to splendent luster. It crystallizes in the trigonal crystal system as equant, distorted prisms with trigonal pyramid terminations.