Russia has the distinction of containing within her borders supplies of every known mineral. As regards European Russia, the chief deposits of mineral wealth are found in the Urals and the Caucasus. Asiatic Russia showed an equal diversity and wealth of mineral deposits, particularly as regards gold. Other minerals found were, iron, graphite, salt, manganese, gypsum. The coal-fields of European Russia had shown a remarkable increase in output during the first decade of the twentieth century, the home supply was only able to satisfy approximately 80 per cent. The Donetz coal-field was the main source of supply for the home market. Russia's deficiencies as regards coal supplies were partly compensated for by her rich oil-fields, which provided her with an alternative fuel of great value. The first products obtained by distillation of crude oil are inflammable, such as gasolene, benzene, petrol. The opening of the Transcaucasian railway in 1883 gave petroleum access to the external market by the cheapest route.