In Colorado, as in most parts of the world, building stone for local use is quarried locally. Two of the state’s stones, however—Yule Marble from the Crystal River Canyon, and Lyons Sandstone of the Front Range—have been more widely used. The Yule Marble, or Yule Colorado Marble, was produced by metamorphism of Leadville Limestone in an area intruded by the Treasure Mountain Granite, thirty-five miles south of Glenwood Springs. This exquisite marble, which has graced many famous monuments and buildings (among them the Lincoln Memorial and the Tomb of the Unknown Soldier), is known for its almost uniform snowy whiteness and regular, fine crystallization. Although its beauty, massive character, and uniformity made it a sought-after ornamental stone, quarrying was economically marginal because of the remoteness of the site. In spite of this, nearly $7,000,000 worth of the marble was produced before the quarry closed in 1940. [Illustration: Pure white marble was quarried for many years at the Yule Colorado Marble Quarry, about three miles southeast of the village of Marble. (U. S. Geological Survey photo)] The Lyons area, north of Boulder, provides pink, hard, even-grained sandstone which splits readily into slabs or flagstones. These are used in the Denver-Boulder area for sidewalks and patios as well as for facing buildings. Quarries owned by the University of Colorado provide a constant supply of handsome facing material and flagstone for new university buildings, although in recent years the high cost of stone construction has limited its use on the campus. [Illustration: Lyons Sandstone is quarried near Lyons, Colorado. The salmon-colored sandstone splits along surfaces defined by slight differences in size and arrangement of the sand grains. (John Chronic photo)] [Illustration: Most of the buildings of the University of Colorado are faced with Permian Lyons Sandstone, which is widely used for buildings and flagstones throughout the Boulder-Denver area. The University Museum, shown here, was established in 1902, and contains over a million scientific specimens, including many Colorado fossils and minerals. Exhibits in the Hall of Earth portray Colorado’s geologic history. (Tichnor Bros. photo)]