Iron (Inventory)/Crust
From LagWiki
The Crust field of the Iron section should be used to list stations which exhibit a crust of iron.
Iron crusts are secondary accumulations of iron usually on bedrock which are not an integral part of the underlying structure. Iron crusts vary in color from dark brown to rusty red and may exhibit a variety of colors in this range.
Iron crusts are rare and are usually found in backreef areas with plenty of sand and other minerals mixed into the limestone.
See also