bortz

Noun

 * 1) Diamond of inferior quality, commonly used for drill tips; abrasive diamond powder; bort.
 * 2) * 1906 September, X-Rays and a Diamond Thief, Popular Mechanics, |%22bortzes%22+diamond+-intitle:%22%22+-inauthor:%22bortz%22&source=bl&ots=eX29kU3W0r&sig=Cv0BTpj6em9oE0mUrRyBSieK5CA&hl=en&sa=X&ei=nrxJULyJDYKPmQX5uIGoBA&redir_esc=y#v=onepage&q=%22bortz%22|%22bortzes%22%20diamond%20-intitle%3A%22%22%20-inauthor%3A%22bortz%22&f=false 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.