About the middle of the 19th century two furnaces in Hardin County in
extreme southern Illinois for a time produced iron from local limonite
ores. The ore is said to have occurred as pellets, chunks, and masses
scattered through soil and clay and apparently was of irregular
distribution. Little can be seen of the deposits today. Their extent is
not known, but they are believed to be of limited size.
The Illinois State Geological Survey carries on a continuous program of
research on the industrial minerals and metals of Illinois and their
uses.
In addition to the investigations mentioned in this booklet, many others
have been made or are in progress. Such studies are necessarily a
continuing activity if the full potentialities of Illinois mineral
resources are to be realized, for industry continually demands new raw
materials and changes its requirements for those now used.
The Survey has issued numerous reports that deal with the resources
discussed here and mimeographed lists of these are available upon
request.
If reproduction is made of the material herein, acknowledgment of the
Illinois State Geological Survey is requested.