They are all hail-fellow-well-mets.

Potassium feldspars are commonly found in igneous rocks.

Glassy feldspars are commonly found in igneous rocks.

He really needs his bumps felt to learn a lesson.

I want my bumps felt.

He is a skilled fell runner.

Fell runners are known for their endurance and agility in mountainous terrain.

I enjoy fell running in the mountains.

Her last name is Felt.

My friend's last name is Feldmann.