The official gemstone of South Dakota is actually the
multicoloured rock, Fairburn Agate, but the official mineral stone
Quartz. The common pink rock you can see all over the exposed
landscapes of the Midwestern state is a marker of how common this
stone is there - it can be found in both the open air with six
sides to the formation or underground inside other rocks with a
more spherical shape.
In Black Hills National Forest, south of Custer, Rose Quartz has
been found in plentiful supply. Mining is no longer in operation
there, but the southern Black Hills have brought vast quantities of
Rose Quartz to us and made it one of the best-known gemstones of
the world over the years.
It is, in fact, more abundant in South Dakota than it is
anywhere else in the world, thanks to its presence in the western
grasslands, too. Collectors have made regular trips to the state
for years to get their hands on the prized gemstone - in particular
in the Black Hills, where collecting is allowed (elsewhere,
permission is required).