This sample of loellingite is displayed in the Smithsonian Museum of Natural History. Loellingite is an arsenide of iron with the composition FeAs2. The sample at left is about 20 cm across and is from Sterling Hill mine, Ogdensburg, New Jersey. It is described as loellingite with willemite and fayalite.
This mineral is also known as lollingite and Mindat opts for that spelling.