Masashi is my best friend.

Naomasa is my best friend.

I think his answer is correct.

This rock is mainly composed of anorthite.

This rock contains a lot of neutral feldspar, especially andesine.

Plagioclase is one of the main components of the earth's crust.

She was wearing a moonstone necklace.

This rock contains sanidine.

The nucleus is the central part of a syllable in phonetics.

This country maintains its sovereignty.