Mayfair Showroom Make an appointment Proudly housed in London's luxury quarter of Mayfair, 77 Diamond has unrivalled access to over 80% of the world's global diamond market. A trip to our showroom will enable you to collaborate with us on a journey that sees you finding something is made to your exact requirements. Paired with one of our expert advisors, you will be given a personalised service that helps you find the high quality affordable diamond jewellery or loose diamonds that you are looking for. Since 1713, Hanover Square has been the home of some of the world's most fashionable residents. From its original development by the1st Earl of Scarbrough who subsequenty became one of the first residents on the square to the current home of publications such as Vogue, Tatler and Vanity Fair, 77 Diamonds is happily housed in a piece of British heritage.