Nelsonite is an igneous rock primarily constituted of ilmenite and apatite, with anatase, chlorite, phosphosiderite, talc and/or wavellite appearing as minor components. It was named for Nelson County, Virginia, and is also found in that state's Amherst and Roanoke counties. At one time, it was mined for the extraction of titanium dioxide. In 2016, the Virginia legislature designated it as the official State Rock of Virginia.  While not mined in Virginia today, occurrences in New York, West Virginia and Quebec have been studied. Nelsonite is currently mined in China for rare-earth elements. 
- "SB 352 Nelsonite; designating as state rock, etc". State of Virginia. Retrieved 2016-05-11.
- "Nelsonite State Rock Initiative". Piedmont Virginia Community College. Retrieved 2016-09-14.