Analyzing materials in the microscopes: From the Sorby thin sections up to the non-destructive large chambers

One hundred and sixty five years ago, Henry Clifton Sorby developed a revolutionary technique to prepare thin and polished sections of rocks and minerals to be observed by transmission and reflectance in the optical polarized light microscopes. Nowadays, Sorby’s methods are still employed for near all inorganic materials with scarce modifications. The optical microscopy subject is essential for rocks analysis; it is an irreplaceable technique for specific complex samples, such as twinned-exsolved feldspars and it must be preserved in the geosciences curriculum. However, for many valuable and common specimens we observe a strong growing of non-destructive techniques coupled to the large chambers of modern microscopes including new chemical, molecular, luminescent, metrical, imaging and structural probes. Suitable explanations for the thin sections decreasing in research laboratories could be: (i) the undesirable cutting of the specimen; (ii) the contamination of surfaces by abrasives and glues; (iii) the e...