The invention provides: —A hydrophilic dehydrated partially purified bone replacement material of natural origin, wherein substantially all non-collagenous organic material is removed while inorganic, porous osseous structure and collagenous structure of natural bone are substantially preserved, characterized in that the bone replacement material contains 0.05 to 1.5 w/w % of at least one of a saccharide or a sugar alcohol, and 0.7 to 5.6 w/w % of a phosphate group selected from the group consisting of phosphate HPO42− and H2PO4−, this phosphate group being part of a physiologically acceptable salt and—a process for preparing a hydrophilic dehydrated partially purified bone replacement material.