In
optical mineralogy and
petrography, a thin section is a thin slice of a
rock,
mineral,
soil, pottery, bones, or even metal sample, prepared in a laboratory, for use with a polarizing
petrographic microscope,
electron microscope and
electron microprobe. A thin sliver of rock is cut from the sample with a
diamond saw and ground optically flat. It is then mounted on a glass
slide and then ground smooth using progressively finer abrasive grit until the sample is only 30 micrometres (0.0012 in) thick. This image shows a thin section of
Siilinjärvi apatite ore from Finland in cross-
polarized transmitted light; the specimen depicted here is approximately 36.6 mm (1.44 in) wide by 20 mm (0.79 in) high.Photograph credit:
Kallerna