In this proposal we aim to investigate the structural evolution and the P-T stability range of two hydrated borates species, inyoite and jadarite, of which elastic parameters (i.e., thermal expansion coefficient, bulk volume compressibility, elastic anisotropy) and P-T stability fields are currently unknown. Such investigations will provide information about the phase stability of these minerals which can be potentially employed as aggregates in neutron-shielding concretes. Previous experiments at high-pressure conducted on other hydrated borates revealed the presence of several phase transitions. Therefore, the high-pressure data of inyoite and jadarite will be compared with our previous results on other borates species, improving our knowledge on this class of minerals at high-pressure conditions.