| Similarity | Rank | |
|---|---|---|
| devonian | 0.914 | 17422 |
| permian | 0.905 | 18568 |
| palaeozoic | 0.901 | 17635 |
| precambrian | 0.900 | 28924 |
| silurian | 0.900 | 24411 |
| triassic | 0.892 | 19513 |
| pleistocene | 0.883 | 19850 |
| cretaceous | 0.877 | 15845 |
| dalradian | 0.868 | 31062 |
| mesozoic | 0.866 | 21369 |
| metamorphic | 0.866 | 30217 |
| eocene | 0.862 | 39949 |
| carboniferous | 0.859 | 10443 |
| proterozoic | 0.855 | 68404 |
| archaean | 0.855 | 68387 |
| chert | 0.852 | 49404 |
| miocene | 0.852 | 31987 |
| gneiss | 0.849 | 38681 |
| facies | 0.848 | 23456 |
| lewisian | 0.848 | 43492 |
| metasedimentary | 0.845 | 73812 |
| igneous | 0.843 | 20899 |
| breccia | 0.843 | 37637 |
| namurian | 0.838 | 53188 |
| glaciation | 0.834 | 30769 |