[1] Spruce Pine district is one of the largest suppliers of high-purity quartz, which is used in the manufacture of silicon for integrated circuits.

[2] The district is named after the town of Spruce Pine, which is located in the middle of the region and is the hub of major mining activity there.

The pegmatites and country rock are part of the Spruce Pine thrust block, the highest thrust sheet of the Blue Ridge belt, the latter being part of the Tugaloo Terrane which was accreted to North America during the Taconic Orogeny.

[2] A more refined age for the pegmatites within the district has been found through 40Ar/39Ar dating of micas.

[3] The approximate age of the whole district was taken from Sm/Nd dating in the hornblendes, and was found to be from 470 to 450 million years old.

[1] Major minerals include plagioclase, microcline, quartz, and muscovite.

[1] Minerals in this unit include talc, amphibole, chlorite, and chrysotile.

[1] The texture of the mica schist is made up of heterogenous layers of minerals.