how gneiss

The girl munchkin is always proud to identify gneiss. She looks for the characteristic striping. Gneiss is metamorphic, and the stripes form when intense heat and pressure–deep in the earth–turn granite or diorite into a sort of putty. The minerals are able to move a little, and sort themselves out into layers of like-minded (or at least like-chemical-ed) minerals. This large rock was part of a dry stream bed in Highlands, NC.