Research & Medical Tourette Association Annual Scientific Meeting The Tourette Association of America will convene its annual scientific meeting on Thursday, April 20, 2017, at the Bethesda North...
Bort-like heavily twinned diamond from Congo. Bort or boart is a term used in the diamond industry to refer to shards of non-gem-grade/quality diamonds. In the manufacturing and heavy industries, bort is used to describe dark, imperfectly formed/crystallized diamonds of varying levels of opacity.
Most diamonds used as gemstones are basically transparent with little tint, or white diamonds. The most common impurity, nitrogen, replaces a small proportion of carbon atoms in a diamond's structure and causes a yellowish to brownish tint.