Metamorphic rock the foliation is called "gneissosity"), granoblastic (includes granulite, some marbles and quartzite), and hornfelsic (includes hornfels and skarn). Metamorphic rock Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means "change in form". The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 °C) and pressure ( or more), causing profound physical or chemical change. The protolith may be a sedimentary, igneous, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by
Polarization of an algebraic form "n" variables u = ("u", "u", ..., "u"). Suppose that "f" is homogeneous of degree "d", which means that Let u, u, ..., u be a collection of indeterminates with u = ("u", "u", ..., "u"), so that there are "dn" variables altogether. The polar form of "f" is a polynomial which is linear separately in each u (i.e., "F" is multilinear), symmetric in the u, and such that The polar form of "f" is given by the following construction In other words, "F" is a constant multiple of the coefficient of λ λ...λ in the expansion of "f"(λu +