Category: Glossary

Refers to a diamond that glows (fluoresces) strong blue under long wave ultraviolet light; in the past the term was used misleadingly to imply a diamond with superior colour. In fact, some diamonds with a high colour grade that have very strong fluorescence can look oily or milky under daylight.

Diamond cut or shaped into an ellipse and covered with triangular facets in a brilliant cut style.

Type of diamond blemish that that appears as a tiny break out of the edge of a diamond, not large enough to be a called a chip and usually confined to the girdle. Nicks affect the polish grade of a diamond.

One of the most coveted crystal shapes for a rough diamond, with eight triangular faces that look as though two four-sided pyramids have joined together at the base.

Trade term for a diamond that has been badly polished or finished. It has flaws in the overall make.

Type of diamond crystal inclusion where a mineral deposit, or sometimes another diamond, is trapped inside the diamond. Needles look like elongated bubbles of various shapes and sizes.

Diamond mined from the earth, unlike a synthetic diamond, formed completely by nature without any human intervention or treatments.