A diamantaire is sometimes referred to as a "gem-quality diamond

Diamond

In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...

 manufacturer or producer", "master diamond cutter

Diamond cutting

Diamond cutting is the art, skill and, increasingly, science of changing a diamond from a rough stone into a faceted gem. Cutting diamond requires specialized knowledge, tools, equipment, and techniques because of its extreme difficulty....

" and a "graduate gemologist (who specializes in diamonds)."

Such individuals demonstrate considerable expertise in different types of gemstone

Gemstone

A gemstone or gem is a piece of mineral, which, in cut and polished form, is used to make jewelry or other adornments...

s, particularly when it comes to increasing the value and quality of a rough or raw diamond

Diamond

In mineralogy, diamond is an allotrope of carbon, where the carbon atoms are arranged in a variation of the face-centered cubic crystal structure called a diamond lattice. Diamond is less stable than graphite, but the conversion rate from diamond to graphite is negligible at ambient conditions...

.

They are highly-skilled craftsmen or artisan

Artisan

An artisan is a skilled manual worker who makes items that may be functional or strictly decorative, including furniture, clothing, jewellery, household items, and tools...

s who are responsible for cut

Cut

Cut may refer to:* The act of cutting, the separation of an object into two through acutely directed force-Mathematics:* Cut * Branch cut, a concept in complex analysis* Dedekind cut, a partition of rational numbers* Cut-elimination theorem...

ting, polishing and transforming a rough diamond into a finished gemstone ready for setting.

Members of diamond dealing families who have established themselves in the upper echelons of the world diamond industry hierarchy are also often referred to as diamantaires as well.