Glossary

Diamond & Gemstone Glossary

Carat

A unit of gemstone weight equal to 0.2 grams. It should be distinguished from a stone's visible dimensions.

Clarity

An assessment of internal and surface characteristics under the conditions defined by the relevant grading system.

Inclusion

An internal characteristic considered during gemological examination.

Blemish

A feature on the surface of a gemstone.

Shape

The outline of a stone, such as round, oval, or pear.

Cutting style

The arrangement or general pattern of facets used to fashion a gemstone.

Facet

A flat polished surface on a faceted gem.

Table

The large central facet on the crown of many faceted stones.

Crown

The portion above the girdle in a conventionally faceted gemstone.

Pavilion

The portion below the girdle in a conventionally faceted gemstone.

Girdle

The boundary region between the crown and pavilion.

Polish

The assessed condition of a gemstone's polished surfaces within the applicable grading system.

Symmetry

The alignment and arrangement of features considered within the relevant assessment system.

Laboratory-grown diamond

Diamond produced through a manufacturing process, with its origin distinguished from natural formation.

Simulant

A different material used to resemble another gemstone.