Abstract: An artificial bone substitute composition consisting of fibrous collagen in a calcium sulfate matrix for incorporation in the human body for ultimate replacement by the body in a metabolic turnover and which can be rendered porous by a foaming agent. Such a composition is adaptable for osseous repair by adjusting the collagen and the calcium sulfate in varying ratios to suit particular applications and including admixtures of growth factors. The composition is prepared in a method of formulating a resorbable material by immobilizing a collagen material having mechanical strength characteristics within a calcium sulfate material and subjecting the composition to a hydration reaction which passes through a fluid state to a moldable state and to a solid.