What does bort mean?
Bort is the trade name for diamond material that falls short of gem quality — stones that are too flawed, cloudy, irregularly shaped, or fractured to be cut into jewellery. Far from being worthless, bort makes up the majority of most diamond mines' output and is highly valued by industry: it is crushed into abrasive grit or set into the edges and tips of drill bits, saw blades, grinding wheels, and polishing tools, where diamond's unmatched hardness does work no other material can. The term belongs primarily to the vocabulary of mining, geology, and the industrial-diamond trade rather than everyday conversation, and it appears in an older variant spelling, "boart." Bort is a useful word for anyone reading about how diamonds are graded, since it marks the boundary between the sparkling gems of the display case and the unglamorous but indispensable working diamonds of heavy industry.
nounBort is low-grade or imperfect diamond, too flawed or irregular for use as a gemstone, crushed and used chiefly in industrial cutting, grinding, and drilling tools.
- Low-grade or flawed diamond unsuitable for gemstone use, crushed for industrial abrasives and tooling.
"The drill bits were tipped with bort because only industrial-grade diamonds could withstand the abrasion of hard rock."
"Only a fraction of each diamond yield is gem quality; the rest is sold as bort to industry."
"Crushed bort embedded in the saw blade sliced cleanly through the marble slab."
The plural borts is rare; the word more often functions as a mass noun referring to industrial diamond material collectively.
"The parcel contained several small borts suitable only for crushing."
Most diamonds never see a ring — bort, the flawed majority of mined diamonds, does the gritty work of cutting, grinding, and drilling instead.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of bort
Bort entered English in the nineteenth century from trade usage connected to the diamond industry, likely via Dutch sources involved in the diamond-cutting centres of the Low Countries. Its deeper etymology is uncertain, and dictionaries record its origin as obscure. The variant spelling boart reflects the same word in older trade texts. It has no widely accepted cognates in English.
Related word forms
How bort is actually used
Bort is a technical term used mainly in the diamond mining and industrial trades rather than in everyday speech. It carries no figurative or emotional connotations. The variant spelling "boart" also appears in older and trade literature.
Easily confused with bort
Bort is a noun meaning low-quality industrial diamond, whereas bought is the past tense of the verb buy.