Bortzとは 意味・読み方・使い方

名詞

bortz (uncountable)

1. Diamond of inferior quality, commonly used for drill tips; abrasive diamond powder; bort.
   • 1906 September, X-Rays and a Diamond Thief, Popular Mechanics, page 932,

     It is also noticeable that the black diamond, No. 20, a dull and lusterless substance, is as transparent to the X-rays as the brilliants, while the diamond bortz, No. 6, is much less transparent than either, though more so than the imitation, No 19.

   • 1939, Materials Engineering, Volume 10, page 358,

     These main categories of industrial diamonds, gem stones, bortz, and carbonados, are further subdivided into smaller classes. For instance, particularly fine bortz of a round form composed of crystals radiating from a common center are known as ballas.

   • 1951, James Deans Cumming, Diamond Drill Handbook^[1], page 482:

     A large part of the production of the Belgian Congo is crushing bortz.