What is the tool used to inspect carefully and closely at diamond rings?

What is that small tool that those diamond ring makers use to inspect diamonds and make rings, etc? Its like a mini scope that people use to look at its flaws, details, etc. Many diamond ring stores have them. What are they called?|||loupe|||It is a jewelers loupe.|||They are called a "loof" at leat that how it is pronounced i an not sure how to spell it.|||First responder was correct, it's called a "loupe".|||It is called a loupe. This is also the name used in photography to examine photographs closely.|||a loop