The article examines the effect of heat treatment on the phase composition of the diabase rocks of Uzunbulak deposit in Jizzakh region. Issues related to the extraction and study of anortite structural fiberglass materials based on heattreated diabase were investigated. It was found that the process of heat treatment of diabase does not lead to the formation of monomineral products, but the formation of feldspar and pyroxene phases, and in order to obtain monomineral products from diabase it is necessary to add additives.