| Kristallfeldtheorie | crystal field theory |
| Quantenfeldtheorie | quantum field theory |
| Kristallgitter | crystal lattice |
| Kristallographie | crystallography |
| Urknalltheorie | Big Bang Theory |
| Ligandenfeldtheorie | ligand field theory |
| Kristallsystem | crystal system |
| Kristallzucker | granulated sugar |
| Kristallisation | crystallization |
| Kristallwasser | water of crystallization |
| kristallisieren | crystallize crystallise |
| kristallklar | crystal clear |
| Abstammungstheorie | evolutionary theory |
| Staatstheorie | theory of the state |
| Stammbaumtheorie | tree model |
| Knotentheorie | knot theory |
| Dramentheorie | dramatic theory |
| Graphentheorie | graph theory |
| Hohlwelttheorie | hollow-Earth theory |
| Spieltheorie | game theory |