The hydrous iron oxide -FeO(OH), a mineral having the hollandite structure, named after a mine in Japan. It is a weathering product of FeS, but was found only in milligram quantities. The second occurrence was at the intersection of two streets in Wawatosa, Wisconsin. The mineral formed when a piece of metal from a decayed Soviet satellite struck the road, which had been salted because it was winter. The Cl from the road salt had allowed a hollandite structure to form. Akaganéite was also found in lunar rocks brought back for analysis. Because aqueous chlorine must have been present in order for the hollandite structure to form, this was interpreted as implying that water had existed on the Moon. Actually, these samples (as well as those from various meteorites) had contained deliquescent material which had absorbed water from the air.
-FeO(OH), a mineral having the hollandite structure, named after a mine in Japan. It is a weathering product of FeS, but was found only in milligram quantities. The second occurrence was at the intersection of two streets in Wawatosa, Wisconsin. The mineral formed when a piece of metal from a decayed Soviet satellite struck the road, which had been salted because it was winter. The Cl from the road salt had allowed a 
hollandite structure to form. Akaganéite was also found in lunar rocks brought back for analysis. Because aqueous chlorine must have been present in order for the hollandite structure to form, this was interpreted as implying that water had existed on the Moon. Actually, these samples (as well as those from various meteorites) had contained deliquescent material which had absorbed water from the air.