Mellite

Cluster of numerous dark gray to black octahedral mellite crystals. This specimen features some very sharp, and partially translucent octahedron with an edge length of 1.8 cm!

Mellite is actually an organic compound, an aluminum mellitate (benzene hexacarboxylate) hydrate, a rare secondary mineral found in lignite deposits. Crystals of this quality are rarely seen and almost exclusively originate from this small mine, making them the best in their category. It is believed that most mellites from this location were mined before World War II, with few discovered since then.