Given a set of mineral physics parameters and an equation of state we can calculate the density, bulk, and shear modulus for a given phase. However, as soon as we have a composite material (e.g., a rock), the determination of elastic properties become more complicated. The bulk and shear modulus of a rock are dependent on the specific geometry of the grains in the rock, so there is no general formula for its averaged elastic properties. Instead, we must choose from a number of averaging schemes if we want a single value, or use bounding methods to get a range of possible values. The module :mod:`burnman.averaging_schemes` provides a number of different average and bounding schemes for determining a composite rock's physical parameters.
.. autoclass:: burnman.averaging_schemes.AveragingScheme
.. autoclass:: burnman.averaging_schemes.Voigt
.. autoclass:: burnman.averaging_schemes.Reuss
.. autoclass:: burnman.averaging_schemes.VoigtReussHill
.. autoclass:: burnman.averaging_schemes.HashinShtrikmanUpper
.. autoclass:: burnman.averaging_schemes.HashinShtrikmanLower
.. autoclass:: burnman.averaging_schemes.HashinShtrikmanAverage