Editing Polarization (waves) (section)

=== Geology ===
[[File:LvMS-Lvm.jpg|thumb|Photomicrograph of a [[volcanic]] [[sand grain]]; upper picture is plane-polarized light, bottom picture is cross-polarized light, scale box at left-center is 0.25 millimeter.]]
The property of (linear) birefringence is widespread in crystalline [[mineral]]s, and indeed was pivotal in the initial discovery of polarization. In [[mineralogy]], this property is frequently exploited using polarization [[microscope]]s, for the purpose of identifying minerals. See [[optical mineralogy]] for more details.<ref name="Wayne2013">{{cite book|author=Randy O. Wayne|title=Light and Video Microscopy|date=16 December 2013|publisher=Academic Press|isbn=978-0-12-411536-1}}</ref>{{rp|163–164}}

Sound waves in solid materials exhibit polarization. Differential propagation of the three polarizations through the earth is a crucial in the field of [[seismology]]. Horizontally and vertically polarized seismic waves ([[shear waves]]) are termed SH and SV, while waves with longitudinal polarization ([[compressional wave]]s) are termed P-waves.<ref name="Shearer2009">{{cite book|author=Peter M. Shearer|title=Introduction to Seismology|date=2009|publisher=Cambridge University Press|isbn=978-0-521-88210-1}}</ref>{{rp|48–50}}<ref name="SteinWysession2009">{{cite book|author1=Seth Stein|author2=Michael Wysession|title=An Introduction to Seismology, Earthquakes, and Earth Structure|date=1 April 2009|publisher=John Wiley & Sons|isbn=978-1-4443-1131-0}}</ref>{{rp|56–57}}