粗粒 そりゅう玄武 げんぶ いわでしょう
so ryūgembuiwadeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 粗粒玄武岩

1. Probably coarse-grained basalt.

Polite
Presumptive
Conjecture
Geology