硫化 りゅうか鉄鉱 てっこうではありませんでした
ryūkatekkōdewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 硫化鉄鉱

1. Was not iron pyrite.; Was not a sulfide ore.

Past/Perfective
Negative
Polite
Formal Register