Natural

Part of the original “skin” of a rough diamond that has been left on the polished diamond. Naturals affect the polish grade of a diamond, but do not have a significant impact if confined to the girdle area where they are usually located.

Moissanite

Near-colourless, slightly oily looking man-made material that is often used to imitate diamond – a diamond simulant.

Moh’s Scale

Scale from for classifying the relative hardness used for gemstones, based on the ability of harder gemstones to scratch softer ones. Moh’s scale ranges from 1 to 10, with 10 being the hardest. Diamonds are the only material on earth to rate as a 10.

Master Set

Set of certified and registered diamonds, with known colours against which other diamonds are compared to establish their colour. A diamond master set is neccesary  for accurate colour grading. A first generation diamond master set is available to any diamond merchant or jeweller.

Marquise Cut

Diamond cut or shaped into an oval with pointed ends. Also called a ‘navette,’ which is the French word for “little boat,” as the shape is similar to that of a boat’s hull.

Loupe

Hand held magnifying lens. Diamond clarity must be graded with a 10x loupe that is corrected for spherical and chromatic aberration.