The Collaborative International Dictionary
Petrography \Pe*trog"ra*phy\, n. [Petro + -graphy.]
The art of writing on stone.
The scientific description of rocks; that department of science which investigates the constitution of rocks; petrology.
Wiktionary
alt. 1 (context petrology English) the branch of petrology that deals with the scientific description and classification of rocks 2 The art of writing on stone. n. 1 (context petrology English) the branch of petrology that deals with the scientific description and classification of rocks 2 The art of writing on stone.
Wikipedia
Petrography is a branch of petrology that focuses on detailed descriptions of rocks. Someone who studies petrography is called a petrographer. The mineral content and the textural relationships within the rock are described in detail. The classification of rocks is based on the information acquired during the petrographic analysis. Petrographic descriptions start with the field notes at the outcrop and include macroscopic description of hand specimens. However, the most important tool for the petrographer is the petrographic microscope. The detailed analysis of minerals by optical mineralogy in thin section and the micro-texture and structure are critical to understanding the origin of the rock. Electron microprobe analysis of individual grains as well as whole rock chemical analysis by atomic absorption, X-ray fluorescence, and laser-induced breakdown spectroscopy are used in a modern petrographic lab. Individual mineral grains from a rock sample may also be analyzed by X-ray diffraction when optical means are insufficient. Analysis of microscopic fluid inclusions within mineral grains with a heating stage on a petrographic microscope provides clues to the temperature and pressure conditions existent during the mineral formation.
Usage examples of "petrography".
The core drillings, the seismic tomography, the petrography and magnetometry and analytical chemistryall of the tools of physical geology he found interesting and was adept at using and interpreting, but at heart what he most liked was just walking in the territory with a hammer and a hand lens, looking at the terrain and picking up rocks.
The core drillings, the seismic tomography, the petrography and magnetometry and analytical chemistry—.