Rock Cycle [More important than you think! When picking rocks for hardscapes you want to use Metamorphic rock in most cases, especially with water (so it doesn't leach anything into the water) but it is also important to know what type of rockscape your c
Disharmonic folds in gneiss. Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks.
Lewisian Gneiss Rock, Isle of Lewis -the Geology of the Outer Hebrides is important - as the predominant rock type is a Lewisian Gneiss - a metamorphic rock which is astonishingly up to 3 billion years old, making it the oldest rock in Britain - two thirds the age of the Earth.