Poorly crystallized diamonds used for industrial cutting and abrasion.(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.
Use "bort" in a sentence
"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."