| Hardness (Mohs) | Mineral | Group |
| 4 | Cobaltocalcite | Calcite |
| 4 | Creedite | |
| 4 | Epistilbite | Zeolites |
| 4 | Fluorite | |
| 4 | Kovdorskite | |
| 4 | Rhodochrosite | |
| 4 | Spherocobaltite | |
| 4 | Tugtupite | |
| 4.06 - 4.08 | Hodgkinsonite | |
| 4 - 4.5 | Austinite | |
| 4 - 4.5 | Bastnaesite | |
| 4 - 4.5 | Carletonite | |
| 4 - 4.5 | Huebnerite | |
| 4 - 4.5 | Smithsonite | |
| 4 - 5 | Apophyllite-(Na) | |
| 4 - 5 | Friedelite | |
| 4 - 5 | Triphylite | |
| 4 - 5 | Xenotime | |
| 4 - 8 (!) | Tiffany Stone | |
| 4.5 | Bultfonteinite | |
| 4.5 | Colemanite | |
| 4.5 | Legrandite | |
| 4.5 | Parisite | |
| 4.5 - 5 | Apophyllite-(OH and F) | |
| 4.5 - 5 | Augelite | |
| 4.5 - 5 | Ekanite | |
| 4.5 - 5 | Gaspeite | |
| 4.5 - 5 | Hemimorphite | |
| 4.5 - 5 | Pectolite | |
| 4.5 - 5 | Scheelite | |
| 4.5 - 5 | Yugawaralite | |
| 4.5 - 5.5 | Ammolite | |
| 4.5 - 5.5 | Carrollite | |
| 4.5 - 7 (!) | Kyanite | |