Marble Thin Section

Rocks under the microscope.

Marble thin section. Tremolite marble the term marble in geology is restricted to metamorphic rocks in which the carbonate minerals have recrystallized. It is formed by dynamic metamorphism at high temperatures and high pressures that aligns the grains of mica hornblende and other flat or elongated minerals into thin layers or foliation. Shape isotropy and relief distinctive.

High 17 40 ve extreme pinky buff colours occasional. The word marble derives from the greek màrmaron crystalline rock shining stone. Rock forming minerals of metamorphic rocks in thin section a work in progress 1 olivine.

Limestone is the protolith of marble. Polarised light micrograph of a sample of marble in thin section. These are photomicrographs very thin slices of rock seen in plane polarised light or between crossed polarisers when the colours seen are produced by interference of light.

Marble is normally white in colour but is often flecked with black green brown and red. Pyrite fes 2 named in antiquity from the greek pyr fire because sparks flew from it when hit with another mineral or metal. May have zones or trails rich in inlcusions of quartz biotite etc which may show s or z shapes.

Crystals rounded or equant if well formed may have 6 or 8 sides in thin section. In thin section the sample can be seen to contain abundant rounded and sometimes deformed dark crystals of pyroxene diopside and hornblende within a fine grained crystalline carbonate groundmass. This is a thin section taken in transmitted light a technique that reveals the diffraction colours of the micaschist but leaves the garnets as black areas as they are opaque.

This process generally increases the average grain size which gives marble its sparkling appearance. It is composed of calcite sometimes with accessory minerals such as graphite pyrite or ilmenite. Some common rock types as seen under the microscope.