硫化 りゅうか鉄鉱 てっこうじゃなかったです
ryūkatekkōjanakattadesu

Noun
Desu Copula

The polite, past negative form of 硫化鉄鉱

1. It wasn't pyrite.; It wasn't iron sulfide.

Past/Perfective
Negative
Polite
Casual Register