There are a lot of pebbles at the bottom of this river.

Ishizawa is my best friend.

Vermiculite, in mineralogy, is a type of mineral and is used for various purposes due to its characteristics.

A neutron is part of an atomic nucleus.

He tripped over the pebble at his feet.

His intention was clear.

Harry was searching for the Philosopher's Stone.

He picked up a stone and threw it.

His strong will led him to success.

My father is an excellent doctor.