The Black Diamond (Den Sorte Diamant) is a modern waterfront extension to the Royal Danish Library 's old building on Slotsholmen in central Copenhagen, Denmark. Its quasi-official nickname is a reference to its polished black granite cladding and irregular angles. The Black Diamond was completed in 1999 as the first in a series of large-scale cultural buildings along Copenhagen's waterfront.
Apart from its function as a library, the building houses a number of other public facilities and activities, most of which are located around the central, toplit atrium which cuts into the building with a huge glazed front facing the harbour. The facilities include a 600-seat auditorium, the Queen's Hall, used for concerts, events, theatrical performances and conferences. There are also exhibition spaces, a bookshop, a restaurant, a café and a roof terrace.Two museums are based in the Black Diamond, the National Museum of Photography and a small museum dedicated to cartoon art.
In the early 1990s, the Danish Ministry of Cultural Affairs launched an international architecture competition for the design of an extension to the Royal Library on Slotsholmen. The competition attracted plenty of Danish and international architectural firms and ultimately Schmidt Hammer Lassen was chosen as the winner in 1993. Construction started in 1995. The cost of the building was DKK 465,000,000. The Black Diamond was inaugurated on 7 September 1999 and opened to the public on 15 September 1999.
The basic shape of the Black Diamond is a box which leans to the left as seen from the harbour as well as towards the water. At the same time it expands slightly from the bottom and up and from north to south, giving it a distorted, prismatic shape. The building is clad in black granite of a type known as Absolute Black, which was mined in Zimbabwe and then cut and polished in Italy. A broad, glazed "crevasse" cleaves the facade into two, letting natural light into the central atrium inside the building. A glazed band also runs along the building's ground floor in its full height to allow for panoramic views of the waterfront from the inside while, at the same time, aiming to give the Diamond a floating appearance when seen from the water.
In contrast to the stringent and dark exterior the atrium creates a bright and organic central space in the library. It is toplit and bounded by wavy balconies. From the atrium an travelator leads up to the C level which holds the main library facilities. The Link is a connecting walkway running from the foyer of the old main building of the library through a skywalk above Christians Brygge and the atrium along a gangway to the glazed facade with sweeping views of Christianshavn and Islands Brygge across the harbour.
The Royal Library on Slotsholmen is not a public library where it is possible to locate and pick the books from open shelves and then borrow them for use outside the library. On the contrary, the books have to be ordered either through online or by filling out a requisition form in the catalogue room. The books can then be collected the next day.