The glass factory owned by Idrija and situated at Zagorje ob Savi was the first glass factory in the former Austrian monarchy, which used for burning of glass-works furnaces coal instead of wood. The inhabitants of Idrija decided to have the factory built in a coal-mining area, because there was not enough wood near Idrija for the glass factory, which was needed for production of fire-proof bottles for sublimation of quicksilver. Until then they imported such bottles from Czechoslovakia, but owing to his expenses — more than 5.000.__ gld. yearly — they wished to have their own glass factory. In addition to the fire-proof booties the glass factory at Zagorje also produced ordinary white and green glass and flat window panes. As this glass was of lower quality than the Czech glass, and transportation to Idrija was expensive, the Czech bottles were cheaper. The glass factory was making a loss, and in 1817 it stopped working, in 1821 it was sold. It existed for another hundred years (until 1928), and then it was removed complete to Rogaška Slatina.