Diamond Anatomy

A diamond is a single crystal of ordered carbon — but a polished diamond is a precise piece of geometry with a vocabulary all its own. Knowing the parts is the first step to reading a grade, a certificate, or the proportions that give a stone its life.

The parts of a diamond

• Diameter — the width of a polished stone, measured from edge to edge across the girdle.
• Table — the largest facet, the flat plane on the very top of the diamond.
• Crown — the upper portion, from the table edge down to the girdle.
• Girdle — the narrow band at the diamond’s widest point, where crown meets pavilion. It may be bruted (frosted), polished, or faceted.
• Pavilion — the lower portion, sloping from the girdle down toward the point.
• Culet — the small facet, or point, at the very bottom of the pavilion. Ideally it is small to none, so no light leaks through.
• Depth — the total height from table to culet, the figure behind a stone looking “deep” or “shallow”.

Why the names matter

Every grade and every proportion is described in these terms. A table that is too large floods the stone with brilliance at the cost of fire; a pavilion cut too deep or too shallow lets light escape instead of returning it. Read together — table, crown angle, girdle, pavilion depth, culet — the anatomy is the cut, told as numbers.