A diamond district is an area where the cutting, polishing, and trade of diamonds and other gems takes place. There are a number of these districts around the world, including:
Antwerp diamond district, Belgium
Surat Diamond Bourse, Surat, India
Diamond Exchange District, Israel
Hatton Garden, London, England
Jewellery Quarter, Birmingham, England
Diamond District, Manhattan, New York, United States
Jewelers' Row, Philadelphia, United States
Jewelry District, United States
Jewelry District, Rhode Island, United States
Jewelers' Row, Chicago, United States From Wikipedia