Auricellite

Auricellite is a mineralogical term that historically referred to a naturally occurring mineral composed primarily of aluminum oxide (Al2O3) and iron oxide (Fe2O3). While the name auricellite was once in common use, it is now considered an obsolete or discredited mineral name by the International Mineralogical Association (IMA). This means that under current mineralogical classification standards, auricellite is not recognized as a distinct mineral species.

The composition attributed to auricellite, namely a mixture of aluminum oxide and iron oxide, is more accurately described by other recognized mineral phases. Specifically, aluminum oxide is most commonly found in nature as the mineral corundum, which encompasses varieties like ruby and sapphire. Iron oxides, on the other hand, are represented by a variety of minerals such as hematite (Fe2O3), magnetite (Fe3O4), and goethite (FeO(OH)).

The reason for auricellite's discreditation likely stems from the fact that it represented a natural occurrence of these common oxide components without a uniquely defined crystal structure or chemical formula that would distinguish it as a separate mineral entity. Modern mineralogy relies on precise chemical analysis and crystallographic data to define and classify minerals, ensuring that each name corresponds to a specific, reproducible substance. Therefore, while the term auricellite may appear in older literature, modern geological and mineralogical studies would refer to the specific aluminum and iron oxide components present in the sample.