| Author: | Illinois State Geological Survey |
| Subject: | QE, Petrology -- Illinois, Mineralogy -- Illinois |
| Format: | Electronic text |
| Date issued: | 2021 |
| Language: | English |
| Publisher: | Project Gutenberg, |
| Rights: | Public domain in the USA. |
| Download link: | Guide to Rocks and Minerals of Illinois [electronic resource] / Illinois State Geological Survey |