platarsite

The story

1. Proto-Indo-European*pleth₂-
2. Proto-Indo-European*pléth₂us
3. Proto-Hellenic*plətús
4. Ancient Greekπλατύς (platús)
5. Vulgar Latin*plattus
6. Spanishplata
7. Spanishplatina
8. Englishplatinum
9. Proto-Indo-European*ǵʰelh₃-
10. Proto-Indo-European*ǵʰl̥h₃enyom
11. Proto-Indo-Iranian*ȷ́ʰr̥Hanyam
12. Proto-Iranian*jr̥Hanyam
13. Old Median*zaranyam
14. Old Median*kā
15. Old Median*zaraniyakā
16. Middle Persian*zarnīk
17. Classical Syriacܙܪܢܝܟܐ (zarnīḵā)
18. Arabicالزَرْنِيخ (az-zarnīḵ)
19. Medieval Greekἀρσενικόν (arsenikón)
20. Latinarsenicum
21. Middle Frencharsenic
22. Middle Englisharsenik
23. Englisharsenic
24. English todayplatarsite

Blend of platinum + arsenic + -ite.