What is Virtual Microsope?

Virtual Microscope (Petroscan system) allows digitisation of entire rock thin sections at high resolutions, preserving the functionality of a conventional petrographic microscope. This includes views in plane polarized light and crossed polarized light at all rotation angles.

The unique and innovative character of the PetroScan system results from the interaction of hardware and software based on the Kansy interpolation that was developed at Fraunhofer FIT. This method caculates the extinction behavior of minerals in 360 degrees rotatation range using only few scan angles, reducing the scan time and amount of data, without the loss of information. Samples can be viewed in a virtual microscopy environment with freely adjustable image magnification and polarization angle.

Download the software

Here you can download the Petroscan Tile Viewer software (works on Windows and Mac):

Terms of use

The PetroScan software is a property of Fraunhofer FIT. It is free to use, copy and distribute for educational, academic or other non-commercial purposes. Commercial use is not allowed without an explicit agreement from Fraunhofer FIT. No part of the software can be modified, adapted, translated, rented or sold without an agreement from Fraunhofer FIT. 

The software is provided 'as is' without warranty of any kind. The users are responsible for all the consequential, incidental or direct damages incured from the use of this product.

Petroscan for Research

Petroscan allows quantitative analysis of giga pixel images. It's advantage is the precise overlapping of ppol and xpol layers, allowing the quantification of the crystal extinction behaviour and image analysis combining the information between the scanned layers. It contains a built-in toolbox for displaying and thresholding the intensity, saturation and hue vallues as well as creation of "phase maps".

Some of the uses includes porosity estimation, calculation of mineral composition and illustration of lattice misorientations within the individual mineral grains.

                                  Picture_2948 - Petroscan for research

Petroscan for Teaching

An example of a Virtual Microscopy based course is "Microtectonics" that has been run at RWTH Aachen university for several years.
The structure of the course is based on the Passchier's and Throuw's book "Microtectonics". Each class starts with a short introduction in one of the deformation processes common in crustal rocks. It followed by an hour-long discussion, where typical microstructures of the introduced process is recognized in a digitised thin-section.

Collaborate with us

Digitised ppol and xpol layers can be georeferenced and overlied with other data layers (e.g. SEM, EBSD, CL), integrating the different methods and providing a larger context to the microstructures. If this can benefit your project, let us know.

We are also looking for new thin-sections from key geology outcrops for teaching purposes. They can be added to our thin-section library, which will be shared openly with the whole geoscience community.   

Download the sample library for the "Microtectonics" course

Brittle deformation - localized cataclasis bands

Picture_2944 - Utah sandstone Porous sandstone adjacent to regional faults. Featuring highly localized cataclastic bands, microfracturing and fragmentation. Some copper precipitation. Courthouse Junction, Utah.

Paper: Ballas, G., Fossen, H., Soliva, R. (2015). Factors controlling permeability of cataclastic deformation bands and faults in porous sandstone reservoirs. Journal of Structural Geology, 76, p.1-21.

Brittle deformation - cataclasite

Picture_2940 - Naif cataclasiteGranite cataclasite, consisting of quartz, feldspar, biotite. Featuring fractal fragmentation, microfaults, marked by feldspar twins and some crystal-plasticity in quartz. Naif, Austria.



Picture_2936 - Ivrea pseudotachylitePseudotachylite with injection veins and cataclastic fragmentation in a feldspatic protolith. Ivrea shear zone, Italy.

Paper: Pittarello, L., Pennacchioni, G., Di Toro, G. (2012). Amphibolite-facies pseudotachylytes in Premosello metagabbro and felsic mylonites (Ivrea Zone, Italy). Tectonophysics, 580, p. 43-57.

Pressure solution 

Picture_2937 - Kohlenkalk pressure solutionPressure solution in bioclastic limestone. Featuring trunkated bioclasts, solution seams and stylolites. Later hydrocarbon transport along the stylolites. Kohlenkalk, Germany.

Pressure solution

Picture_2931 - Ara stylolitesPressure solution in dolomitized oolithe limestone, cemented with anhydrite. Featuring trunkated ooliths, microveins and stylolites. Later hydrocarbon transport along the stylolites. Ara reservoir, Oman.

Paper: Becker, S., Reuning, L., Amthor, J.E., Kukla, P.A. (2019). Diagenetic processes and reservoir heterogeneity in salt-encased microbial carbonate reservoirs (late Neoproterozoic, Oman). Geofluids, p. 1-19, Article ID 5647857.


Syntaxial veins

Picture_2942 - Oman syntaxial veinsFibrous and blocky syntaxial veins. Featuring two sets of veins with different microstructures, as well as related microveins. The host rock consist of pelloids with sparitic cement. Oman.

Paper: Arndt, M., Virgo, S., Cox, S.F., Urai, J.L. (2015). Changes in fluid pathways in a calcite vein mesh (Natih Formation, Oman Mountains): insights from stable isotopes. Geofluids 14, p. 391-418.


Antitaxial veins

Picture_2941 - NY antitaxial veinsFibrous antitaxial veins in a mica schist. Featuring oblique veins with curved fibres, local displacment and fibre growth around porphyroclasts. New York, US.

Paper: Passchier, C.W., Urai, J.L. (1988). Vorticity and strain analysis using Mohr diagrams. Journal of Structural Geology, 10(7), p. 755-763.

Folding and cleavage

Picture_2938 - Mosel cleavageFolding in a phyllite, featuring 2 cleavages, pressure solution, microveins in two types of lithologies. Mosel, Germany.

Paper: Schmatz, J. and Urai, J.L. (2011). The interaction of migrating grain boundaries and fluid inclusions in naturally deformed quartz: A case study of a folded and partly recrystallized quartz vein from the Hunsrück Slate, Germany. Journal of Structural Geology, 33(4), p. 468-480.

Brittle-viscous deformation

Picture_2934 - Granite mylonite Anne-Marie BoullierGranite mylonite featuring cataclasis in felspar and and crystal plasticity and dynamic recrystallization in quartz. Location???

Sense of shear

Picture_2932 - Cap de Creus sigma clast myloniteMylonite featuring quartz and feldspar sigma clasts, mica fishes and quartz sheath folds. Cap de Creus, Spain.

Paper: Fusseis, F., Handy, M.R., Schrank, C. (2006). Networking of shear zones at the brittle-viscous transition (Cap de Creus, NE Spain). Journal of Structural Geology, 28(7), p. 1228-1243.

Crystal plasticity and dynamic recrystallization

Picture_2939 - mylonite with boudins Cap de CreusQuartz mylonite with feldspar boudins. Cap de Creus, Spain. Features dynamic recrystallization in quartz and feldspar.


Metamorphism and deformation

Picture_2943 - Stettinger Huette mica schistMica schist with garnet porphyroblasts. Consists of muscovite, biotite, quartz, garnet. Featuring evidence of at least 3 deformation events, crenulation cleavage, inclusions in the porphyroblasts, shear sense indicators. Schneeberg complex, Alps.

Paper: Krenn, K., Kaindl, R., Hoinkes, G. (2004). Pumpellyite in metapelites of the Schneeberg Complex (Eastern Alps, Austria): a relict of the eo-Alpine prograde P-T path? European Journal of Mineralogy, 16 (4), p. 661-669.

Salt tectonics

Picture_2935 - Hengelo SaltGamma-irridated halite sample. The cores are relic, inclusion rich sedimentary grains with hopper microstructures. The rims are inlusion free and display subgrains. Hengelo, The Netherlands.

Paper: Schleder, Z., Urai, J.L. (2005). Microstructural evolution of deformation-modified primary halite from the Middle Triassic Rot Formation at Hengelo, The Netherlands.


Picture_2955 - Naxos-boudin-vipCalcite marble with boudinage of amphibolite layer. Deformation twins and recrystallization of calcite, necking. Naxos, Greece

Paper: Virgo, S., von Hagke, C. and Urai, J. (2018). Multiphase boudinage: a case study of amphibolites in marble in the Naxos migmatite core - Solid Earth, 9, 91-113, https://doi.org/10.5194/se-9-91-2018, 2018.


Fluid-rock interaction in peridotite

Picture_2959 - Wadi-Fins-ViP Serpentinization and precipitation of carbonate veins in peridotite. Textbook examples of pseudomorphic replacement of ortho-pyroxene by bastite serpentine and of olivine by mesh serpentine. Olivine shows a crystal preferred orientation indicating a high-temperature crystal plastic farbric. Wadi Fins, Oman ophiolite

Wide-blocky calcite veins in micrite
Picture_2960 - Lilstock vein L4a thumbnailSyntaxial calcite veins in a micritic carbonate host rock.

Paper: Spru┼żeniece, L., Späth, M., Urai, J.L., Ukar, E., Selzer, M., Nestler, B., Schwedt, A. (2021). Formation of wide-blocky calcite veins by extreme growh competition. Journal of the Geological Society, 178 (2).




Literature on PetroScan

Spruzeniece, L. Schmatz, J., Virgo, S., Urai, J.L. (2019). Virtual microscopy for geosciences. EGU blog: Minds over Methods.
Source: https://blogs.egu.eu/divisions/ts/2019/07/23/virtual-microscopy-for-geosciences/

Virgo, S., Heup, T., Urai, L.J. Berglage, T. (2016). Virtual Petrography (ViP) - A virtual microscope for the geosciences. EGU General Assembly, EGU2016-14669.
Source: https://publications.rwth-aachen.de/record/675017675017.pdf

Schmatz, J., Urai, J.L., Bublat, M., Berlage, T. (2010). PetroScan - Virtual microscopy. EGU General Assembly, EGU2010-10061.
Source: file:///C:/Users/Guest/Downloads/EGU2010-10061.pdf

Other samples of interest


Recrystallized marble in Metabauxite

Picture_2961 - Naxos-marble Recrystallized marble in metabauxite with foam texture. Naxos, Greece

Literature: Urai, J.L., Feenstra, A., 2001. Weakening associated with the diaspore–corundum dehydration reaction in metabauxites: an example from Naxos (Greece). Journal of Structural Geology 23, 941-950.

Mylonite Simplon

Picture_2962 - Simplon mylonite Mylonite, Simplon pass (Alps). Quartz ribbons, garnet porphyroclasts.


Mylonite Australia

Picture_2963 - Australian_mylonite-Bresser Mylonite, Australia (location?). 
Literature: ?


Picture_2956 - gabbro-vip Gabbro with poikilitic clinopyroxene, plagioclase, and minor olivine. Pyroxene exsolution.

Sample courtesy Prof. Jürgen Köpke, Universität Hanover

Greenschist-facies metasediment

Picture_2957 - Oman-sole-metasediment Greenschist-facies metasedimentary rock of the metamorphic sole of the Oman ophiolite, with a quartz-carbonate vein. Sample at 203.5 m downhole-depth in Hole BT1B of the Oman Drilling Project (OmanDP).

Literature: Kelemen, P.B., Matter, J.M., Teagle, D.A.H., Coggon, J.A., and the Oman Drilling Project Science Team, 2020. Site BT1: fluid and mass exchange on a subduction zone plate boundary. In Kelemen, P.B., Matter, J.M., Teagle, D.A.H., Coggon, J.A., et al., Proceedings of the Oman Drilling Project: College Station, TX (International Ocean Discovery Program).

Carbonated peridotite with brittle overprint

Picture_2958 - Oman-listvenite-cataclasite Fully carbonated peridotite (listvenite), consisting of magnesite, quartz and chromite. Various vein generations and brittle overprint by localized cataclasites and faults. Sample at 23.5 m downhole-depth in Hole BT1B of the Oman Drilling Project. (OmanDP)

Literature: Menzel, M.D., Urai, J.L., de Obeso, J.C., Kotowski, A., Manning, C.E., Kelemen, P.B., Kettermann, M., Jesus, A.P., Harigane, Y., the Oman Drilling Project Phase 1 Science Team, 2020. Brittle Deformation of Carbonated Peridotite—Insights From Listvenites of the Samail Ophiolite (Oman Drilling Project Hole BT1B). Journal of Geophysical Research: Solid Earth 125, e2020JB020199.