The foliations of gneiss make beautiful swirls and patterns in polished countertops and building slabs. Many so-called granite countertops are actually gneiss. Gneiss makes a gneiss [sic] countertop!
If by useful you mean info on gneiss, it is basically a coarse-grained, foliated, high grade metamorphic rock. Gneiss forms during high grade, regional metamorphism, and can form from amny different parent rocks including shale and igneous rocks. Most gniesses are often granitic in composition and one variety forms from the metaporphism of granite. Gneisses are also named for the dominant material such as biotite gneiss or garnet gniess.
- David Miller