Wallsized USSR Map Made Of Gemstones - This unique map is located in the geological museum of Saint-Petersburg. It is made from gemstones in theÂ Florentine and Russian mosaic technique. 45 000 gemstones 4-6 mm (0.15-0.23 inches) thick were used to make the panel of the map. The size of the map is twenty seven square meters, it is made from 50 000 fragments. The gemstones were being chosen to match the colors and sizes.