The Open University has created a free course on the OpenLearn website, which can be used in conjunction with the Virtual Microscope teaching collections.

You can learn how the polarising microscope works and how to identify minerals and rocks under the microscope in the free OpenLearn course introduction to mineralogy and petrology. These resources represent adapted extracts from a Level 2 Open University geology module, and include:

• minerals in the crystalline state, states of matter, physical properties of minerals in hand specimen, the atomic structure of crystals, crystal defects and twinning, and crystal symmetry and shape 
• minerals and the microscope including: the nature of light, minerals and polarised light, and minerals and the polarising microscope.

The OpenLearn course includes many activities that use the Virtual Microscope – helping you to learn the characteristics of minerals and rocks in thin section.

Useful resources

Optical Mineralogy - this free online website, crammed with mineral descriptions and images, is a wonderful practical resource for students taking their first tentative, bedazzled steps into the seductive world of petrography. Lovingly crafted by Dexter Perkins, Matt Kohn and John Brady, this site features numerous beautiful images of minerals that can be toggled between PPL and XPL with a minimal mouse roll. The authors have focused on providing practical tips on how to identify minerals and distinguish them from each other.

Guide to Thin Section Microscopy by Raith, Raase and Reinhardt (2012) is a complete and detailed guide to the study of minerals and rocks using a polarising microscope. It is freely available on the Open Access Publications section of the Mineralogical Society of America website, along with several other interesting publications.

Handbook of Mineralogy presents >4000 separate pdfs, each with optical, textural and chemical information on a particular mineral species. These are also hosted on the Mineralogical Society of America website.

This Atlas of Metamorphic Minerals on the Oxford University website features thin section images of many common metamorphic minerals.

Liverpool University's GeoHub has, among many excellent resources to support your study of Earth Science, a basic introduction to investigating Rocks in thin section.

Recommended reading

Rocks and Minerals in Thin Section (Second edition) by W.S. MacKenzie, A.E. Adams & K.H.Brodie (2017). A concise, illustrated introduction to observation, description and identification of geological samples in thin section. Aimed at undergraduate level.

Introduction to Metamorphic Textures and Microstructures by A.J. Barker (1998). A useful guide for undergraduate students.

Atlas of Rock Forming Minerals by W.S. MacKenzie & C. Guilford (1980). An accessible pictorial introduction to common rock-forming minerals. A good entry-level undergraduate text.

Atlas of Sedimentary Rocks under the Microscope (Second edition) by A.E. Adams, W.S. MacKenzie & C. Guilford (1984). A pictorial introduction to a range of sedimentary rocks in thin section. Aimed at undergraduate level.

Optical Determination of Rock-Forming Minerals by W.E. Tröger (1980). English version of the German 'determinative tables' that are an invaluable reference for all students of petrology.

An Introduction to the Rock Forming Minerals (Third edition) by W.A. Deer, R.A. Howie & J. Zussman (2013) The mineralogy 'bible' for many undergraduate students, this single volume work covers most of the commonly occurring minerals in igneous, metamorphic and sedimentary rocks.

Microtectonics (Second edition) by C. Passchier & R. Trouw (2005). Aimed at undergraduate students and above, this book contains descriptions and interpretations of a multitude of small-scale structures and textures in deformed rocks.

A Practical Guide to Rock Microstructure by R. Vernon (2004). An illustrated exploration of the processes responsible for a wide variety of microstructures in igneous, sedimentary, metamorphic and deformed rocks. Aimed at senior undergraduate students and above.