Definition of "bort" [bort]

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

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The black diamonds, called bort, are used mainly for arming diamond drills and for polishing other diamonds."
• "In the diamond industry, the term "bort" is used for diamonds that have a rough, rounded form and which lack a distinct cleavage."
• "a steel bar, the first blow broke the blade without affecting the diamond, yet a piece of bort, or diamond dust, splinters, or defective diamonds (all these being called bort), may readily be pulverised in a hard steel mortar with a hard steel pestle."