from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun Poorly crystallized diamonds used for industrial cutting and abrasion.
  • noun A carbonado.

from The Century Dictionary.

  • noun A collective name for diamonds of inferior quality, especially such as have a radiating crystallization, so that they will not take a polish.
  • noun An amorphous variety of diamond, brown, gray, or black in color, and known also as black diamond or carbonado, found massive in Brazil in association with pure diamonds.

from the GNU version of the Collaborative International Dictionary of English.

  • noun Imperfectly crystallized or coarse diamonds, or fragments made in cutting good diamonds which are reduced to powder and used in lapidary work.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun uncountable Poor quality diamond, used for industrial cutting or abrasion; a poorly crystallized diamond.


from The American Heritage® Dictionary of the English Language, 4th Edition

[Probably from Dutch boort.]


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  • Low-quality diamond, in granular aggregate or small fragments, valuable only in crushed or powdered form, esp. for industrial use as an abrasive. (

    1. Poorly crystallized diamonds used for industrial cutting and abrasion.

    2. A carbonado. (American Heritage)

    Bort or boart is a term used in the diamond industry to refer to shards of gem-grade/quality diamonds. In the manufacturing and heavy industries, "bort" is used to describe dark, imperfectly formed/crystallized diamonds of varying levels of opacity. The lowest grade, "crushing bort", is crushed by steel mortars and used to make industrial-grade abrasive grits. Small bort crystals are used in drill bits. The Democratic Republic of the Congo provides 75% of the world supply of crushing bort. (Wikipedia)

    July 9, 2008

  • And here I thought "bort" was just a common Swedish chef ejaculation.

    July 9, 2008

  • Noobly-noot, bort bort!

    July 9, 2008

  • I thought it was a joke from the Simpsons.

    July 9, 2008

  • I may adapt the term crushing bort to refer to a few particularly yawn-inducing acquaintances.

    July 10, 2008

  • For some reason, it sticks in my mind that the standard drinking toast in Iceland is something like "scowly bort".

    Perhaps one of our freshly minted Wordie Icelandic experts might be able to enlighten us further?

    July 10, 2008

  • 2. A carbonado. (American Heritage): Hey, is that the Italian bacon and eggs pasta dish? I love that!

    Ooops! Wrong list...

    July 10, 2008

  • Here's bort in yur eye! Arrrrgh!

    July 10, 2008

  • Mmm... pasta alla carbonara... *drooling*

    July 10, 2008

  • A gem in the rough by report,

    Was Ernest at Doubleday’s sport.

    His diamond exploit

    Though grew less adroit

    And Ernest’s career was a bort.

    Find out more about Ernest Bafflewit

    March 27, 2018

  • Etymonline says: "waste diamonds, small chips from diamond-cutting," 1620s, of unknown origin, perhaps related to Old French bort "bastard."

    June 12, 2021

  • waste diamond is quite a phrase.

    June 12, 2021