LISLE, Ill. (CBS) — It is now official – the chosen rock of the State of Illinois is dolostone.
At the Morton Arboretum in Lisle Monday, Gov. JB Pritzker signed an Illinois signed an Illinois House bill to make it official.
This all started when grade school students from Pleasantdale Middle School in Burr Ridge and Maplebrook Elementary School in Naperville learned that Illinois didn’t have a state rock. So they created a ballot and had students across the state vote on a state rock – and dolostone won.
“Seeing young people use their voices and the democratic process to make change in our state is truly inspiring,” Gov. Pritzker said in a news release. “These young leaders have a bright future of organizing and civic engagement that I am excited to watch. They could not have picked a better rock to represent the strength and stability of Illinois.”
As explained by the Arkansas Geological Survey, dolostone similar to limestone -except principally composed of the mineral dolomite (CaMg(CO3)2), whereas limestone is principally composed of calcite (CaCO3).
Dolostone makes up the majority of the bedrock in Illinois. Its name comes from its original discovery in the Dolomite Alps in northeast Italy.
Illinois does have a number of state symbols – including a state bird (the northern red cardinal), a state flower (the violet), a state tree (the white oak), and a state fish (the bluegill).
As it happens, Illinois also has a state mineral and has since 1965. The state mineral is fluorite (CaF2), glass-like and often colorful mineral for which mining was a multimillion-dollar industry at the southern tip of Illinois at the time, according to the Illinois State Geological Survey.
Fluorite, also known as fluorspar, is not mined anywhere in the United States anymore, the Geological Survey said.