Figure 1. Experimental set-up.

(a) SEM micrograph of a sintered sample showing homogeneous microtexture and grains distribution: ∼ 80 vol% SC olivine (ol)+∼20 vol% Corsica antigorite (atg). (b) D-DIA assembly in a boron-epoxy cube. The sintered sample and its hexagonal boron nitride sleeve are inserted in the graphite furnace, in between alumina pistons. Boron-epoxy cube and hBN are transparent to X-rays. Gold foils (yellow) are used as strain markers. (c) X-ray diffraction pattern used to extract the stress from the lattice strains. For a sample with only 5 vol% of antigorite and 95 vol% of olivine. (d) Unwrapped diffraction pattern and indexing of diffraction peaks.