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Colorado gets an official state rock

Brief by Central Staff

State Symbols – April 2004 – Colorado Central Magazine –

Colorado already had an official state mineral (Rhodochrosite from the Sweet Home Mine near Alma) and an official state gemstone (Aquamarine from Mt. Antero west of Nathrop), and it now has an official state rock: Yule Marble from the quarry in Gunnison County.

After both houses of the legislature passed it, Gov. Bill Owens signed the bill on March 9, and it takes effect on Aug. 4.

It was the result of a project by Girl Scout Troop 357 in Lakewood, who started in October of 2002. They researched the history of the Yule Quarry, and got endorsements from historians, geologists and politicians. They then persuaded Rep. Betty Boyd, a Lakewood Democrat, to carry the bill.

The quarry is near the town of Marble, and its stone was used to build the Lincoln Memorial and Tomb of the Unknown Soldiers in Washington, D.C., as well as more than 40 buildings in Colorado. The stairs and floors of the state capitol building are made of Yule Marble.

According to the Colorado Geological Survey, Yule Marble began as Leadville Limestone — a deposit of shells on an ancient sea floor. Limestone becomes marble through metamorphosis; the tremendous heat and pressure that also transforms crumbly shale into solid slate.

Yule Marble was formed somewhat differently than Vermont and Georgia marbles, so it has the small and uniform grain size that sculptors like. Fractures are more widely spaced, so Yule can be quarried in bigger blocks, too, which accounts for its monumental uses.

Central Colorado does pretty well in the production of official state symbols. The official mineral, gemstone, and rock all come from our counties.

The state tree (Colorado Blue Spruce, Picea pungens) is common on our slopes, as is the state flower (Rocky Mountain Columbine, Aquilegia caerules). The state fish, Greenback Cutthroat Trout (Oncorhynchus clarki somias), can be found in some high streams and lakes. The state fossil, the Stegosaurus, was dug up near CaƱon City. And if you’re driving that direction, you often see the state animal, the Rocky Mountain Bighorn Sheep (Ovis canadensis).

The official state insect is the Colorado Hairstreak Butterfly (Hypaurotis cysaluswas). We’re not sure that we’ve ever seen one, but we should have, since its habitat is scrub oak, and that’s all around us.

Our state bird is the Lark Bunting, a migrant which lives on the plains from April to October. There’s also a state grass, Blue Grama, and an official state tartan, if you want to get a Colorado kilt.

Still to come, perhaps: Official State Predator, Official State Metal, Official State Soil, Official State Rodent, Official State Protozoa (Giardia deserves something, right?), Official State Arachnid (Should we honor the woodtick or the Black Widow?)….