Evidence of growth rate dispersion for symmetry-related opposite faces of centrosymmetric single crystals of ammonium perchlorate is provided. Crystallization experiments conducted by evaporation of a stagnant aqueous solution at room temperature show that some ðhklÞ faces have high and irregular normal growth rates, in time and space, whereas the corresponding ðh k lÞ faces crystallize slowly and steadily. The ðhklÞ faces presenting high and irregular crystal growth also form repetitive inclusions, whereas ðh k lÞ faces are not involved in any formation of vacuoles. As a consequence, it is possible to retrace the crystallization history of a single crystal by analyzing the location of series of inclusions showing the progressive displacement of its center of gravity.

Supplementary InfoInternational audiencea Investigations about the physico-chemical behaviour of fluid inclusions by means of thermal treatments and slow crystal dissolution lead to the evidence of two different kinds of gas bubbles. The results are reproducible for several organic and inorganic crystals obtained in aqueous solutions or organic solvents. Experiments under various pressures highlighted that the solubility of dissolved gases can play a significant role in the number of formed vacuoles. In addition, the nature of the dissolved gas in the mother liquor had an influence on the type of trapped bubbles. Raman spectroscopy confirmed that gaseous bubbles in fluid inclusions were rich in the gas that was dissolved in the mother liquor. Moreover, the pressure inside frozen aqueous fluid inclusions was estimated by measuring the temperature of the non-congruent fusion of the CO 2 clathrate that formed inside the vacuoles at −60 °C. Interferometry experiments were performed in order to visualise the consequences of the presence of vacuoles at the surface of the crystals. This study about fluid inclusion behaviours sheds new light on the formation of 3D defects in single crystals , whose mechanismIJs) of formation is (are) still difficult to understand