Artist Gerhard Marx in conjunction with Spier Architectural Arts recently created an enormous(庞大的) sculptural(雕刻的) mosiac of an aerial(空中的) photograph of Johannesburg, South Africa. Seven professional mosaic artists, together with nine apprentices(学徒) worked for 5 months to complete the project using natural stone such as marble and travertine(石灰华), fragments(碎片) of red brick, ceramic(陶瓷) elements(基础) and chippings of Venetian smalti glass. In the end, the 56-panel aerial image weighs nearly three tons and was presented last month at the 2013 FNB Joburg Art Fair.