This is textbook-twinned Ferberite from the Tazna Mine in Bolivia that has produced the best and largest twin crystals for the species! It's an impressive and hefty, V-twinned Ferberite specimen with wonderful blocky form, sharp faces and excellent submetallic luster. The largest twin component measures 6.7 x 5.5 x 2.5 cm and the smaller 4.1 x 3.7 x 2.1 cm; both display nicely developed terminal faces that are bright and lightly striated. As a species, Ferberite is rarely found in twinned crystals, usually as prismatic, spear-point crystals occurring singly and in groups. This impressive and attractive twin has no damage and is only contacted on the bottom where it was removed from matrix. Extraordinary!