A facet is a flat, polished surface that reflects light. Gemstones are often cut with multiple facets to enhance their brilliance and sparkle.

While "facet" is the most common term, you might also hear terms like:

* Table: The large, flat top surface of a gemstone.

* Culet: The small, flat surface at the bottom point of a gemstone.

* Girdle: The edge of a gemstone that separates the crown (top) from the pavilion (bottom).

However, facet is the most general and widely used term to describe the surface of a gemstone.