Russia: Wallsized USSR Map Made of Gemstones
This unique map is located in the geological museum of Saint-Petersburg. It is made from gemstones in the 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 map of The USSR industrialization” is the whole USSR in scale 1:1 500 000. The size of the map os twenty seven square meters, it is made from 50 000 fragments. The gemstones were chosen to match the colors and sizes. (via English Russia)
More pictures at the link