pyritiferous

The story

1. Proto-Indo-European*péh₂wr̥
2. Proto-Hellenic*pāwər
3. Ancient Greekπῦρ (pûr)
4. Ancient Greekπῠρῑ́της (pŭrī́tēs)
5. Latinpȳritēs
6. Old Frenchpyrite
7. Englishpyrite
8. Proto-Indo-European*bʰer-
9. Proto-Indo-European*bʰéreti
10. Proto-Italic*ferō
11. Latinferō
12. Proto-Indo-European*h₃ed-
13. Proto-Indo-European*h₃édosder.?
14. English todaypyritiferous

From pyrite + -i- + -ferous.