Petrography is a scientific method in Petrology,[1] that is largely based on the study of the appearance of thin, transparent sections of rocks in a microscope[fn 1] fitted with polarizers;[fn 2] in the absence of external crystalline form. As with the minerals in a rock, a mineral often may be readily identified by the determination of some of its optical properties.[2]


  1. Ferdinand Zirkel, German geologist was a pioneer in microscopic petrography, the study of rock minerals by viewing thin slices of rock under a microscope and noting their optical characteristics.
  2. See: Petrographic microscope


  1. Encyclopædia Britannica, Petrology
  2. Encyclopædia Britannica, Optical crystallography
Further reading