Description
The rocks are called slag, a byproduct of iron production in the 18th and 19th centuries. The crushed stone is formed when the furnace reaches a sufficiently high temperature to vitrify the ore. Traces of vitrification are occasionally seen in older slags, and even in modern slags, less incompletely vitrified portions are often found. The rock layer is the slag, which is formed during the smelting of the metal. The slag floats on top of the melt and is discharged from the blast furnace before the metal. Slag comes in a variety of colors and textures. What distinguishes slag from other types of slag is its color and texture. The color can change from light blue, through bright blue and dark blue, to green, to black. The appearance depends, among other things, on the minerals it contains. The structure is glassy and brittle. Slag tiles were cast from the slag, where the liquid slag was poured directly from the furnace into sand molds (see slag shell). In more modern times, limestone tiles were made from slag pellets and lime. People dug roads, insulated house floors, and made pile from cotton-like threads, which were used for insulation. However, this had to be stopped because it turned out that the fine slag needles were destroying the workers' lungs. From the main blast furnace slag and burnt lime, cement was made, and bottle glass was also manufactured. Around the Bergslagen Murade house of slag stone and many other buildings remain today, for example, the ruins of the "Slaggstensslottet" from 1884 in Norhyttan in southern Dalarna. Today, no houses are clad with slag stone, but the colored stone, especially the blue one, is preferred as a starting material for jewelry. Grinded and polished and cut into precious metals, Bergslagsstenen become a popular souvenir from Bergslagen.
