He is an expert in ring theory and has written many papers in the field.

Studying the life cycle of this insect is very interesting.

The benzene ring is a very important concept in organic chemistry.

She was wearing a diamond ring on her ring finger.

He damaged his atlas.

He was fishing using a swivel.

This red sand is very beautiful in color.

The red color in this painting is made with cinnabar.

This gem is made of cinnabar.

In spring, there can be yellow sand flying around.