Rose quartz; photo by Mario's Planet on Flickr (noncommercial use permitted with attribution / share alike)
Official State Mineral Stone of South Dakota
Rose quartz was designated the state mineral stone of South Dakota in 1966 (a pink-colored quartz discovered near Custer, South Dakota in the 1880's). Rose quartz is mined in the southern Black Hills and is used primarily for ornaments and jewelry.
South Dakota also recognizes Black Hills Gold as the state jewelry and Fairburn agate as the state gemstone. All State Minerals & Rocks - Gems & Gemstones