bortz

Definition

Diamond of inferior quality, commonly used for drill tips; abrasive diamond powder; bort.

Example Sentences

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