This sample of stibiconite is displayed in the Smithsonian Museum of Natural History. Stibiconite is a oxide mineral of antimony. It has the composition Sb6O6(OH). This sample of stibiconite at left is about 5x25 cm and is from Catorse, San Luis Potosi, Mexico. The sample is described as being "after stibnite" since it has the characteristic shape of stibnite, shown at right, indicating that the oxidation took place following the sulfide stibnite by replacing the sulfur with oxygen.