The grey matter of the brain is the central part of information processing.

This beautiful zoisite is part of my mineral collection.

Rumors are spreading that he is the culprit, but there must be some reason because 'where there's smoke, there's fire.'

This mineral is called ulexite and has special optical properties.

This stone is a mineral called clinozoisite.

My grandfather contracted poliomyelitis when he was young.

There must be a reason why he is acting suspiciously. It's like the saying, 'Where there's smoke, there's fire.'