Common, coarse-grained variety of quartz that ranges in colour from nearly black through smoky brown. No distinct boundary exists between smoky and colourless quartz. Its abundance causes it to be worth considerably less than either amethyst or citrine. Heating bleaches the stone, the colour sometimes passing through yellow; these yellow pieces are often sold as citrine.
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West range of the Appalachian Mountains in the U.S. It extends along the North Carolina–Tennessee boundary and blends into the Blue Ridge to the east. The highest part lies within the Great Smoky Mountains National Park and includes Clingmans Dome, which at 6,643 ft (2,025 m) is the highest peak. Covered by forests, it was originally the domain of the Cherokee, and the area includes the Cherokee Indian Reservation and parts of the Pisgah and Cherokee national forests. The mountains form a popular resort area that includes part of the Appalachian National Scenic Trail and the Blue Ridge Parkway.
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