C₂H₁₇O₅Si₄₆O₉₂

This sample of melanophlogite is displayed in the Smithsonian Museum of Natural History. Melanophlogite is a oxide mineral with the composition C₂H₁₇O₅Si₄₆O₉₂. The sample at left is about 8 cm across and is from Racalmuto, Agrigento, Sicilicia, Italy. It is described as melanophlogite with sulfur.