Onekaka Iron and Steel was first floated in 1921 with the works becoming operational in 1924 and only ceasing operation in 1935. The ironworks used the limonite ore from nearby to make iron. To smelt
Proposed development for Onekaka (published in 1937 by NZ Truth)
Limonite is an iron ore consisting of a mixture of hydrated iron oxide-hydroxides in varying composition. The generic formula is frequently written as FeO·nH2O, although this is not entirely accurate