Garnet sand

Alma Gulch, Alaska, USA.
Garnet is important silicate rock forming mineral and present in many rock types, although it is almost never major component of a rock. Garnet sand is a sub-type of heavy mineral sand. Garnet is relatively stable mineral and therefore usual component in sands but almost never most abundant part of it.
There are some hard to find exceptions – red and very beautiful sands where garnet is indeed most abundant sand forming mineral. Source rocks of garnets are usually either metamorphic (garnet schist, rarely eclogite) or igneous (aluminium rich granite).