(A) Schematic and not to scale diagram of the Brazilian disk test. The sample (yellow) rests on a section of the mold in a sample holder and is surrounded by a metal cooling shield. These parts were kept in liquid nitrogen until the moment of measurement. A narrow piston descends onto the sample and generates a crack when the force is sufficient. The corresponding mass to the force is measured by a scale. (B) An image series to illustrate the sample size and the crack evolution in a sample.