facet

Any one of the flat surfaces cut into a gem.

This facet of the diamond was masterfully cut to enhance its value.

One among many similar or related, yet still distinct things.

The child's learning disability was only one facet of the problems contributing to his delinquency.

One of a series of things, such as steps in a project.

We had just about completed the research facet of the project when the order came to cancel it.

One member of a compound eye, as found in insects and crustaceans.

A smooth circumscribed surface.

the articular facet of a bone

To cut a facet into a gemstone.