A pourable agglomerated aluminosilicate builder composition comprising(A) from 20% to 70% by weight of at least one finely-divided, synthetically-produced, water-insoluble aluminosilicate compound containing at least some combined water and having a calcium binding power of at least 50 mg CaO/gm of anhydrous active substance and the formula on the anhydrous basis(M.sub.2/n O).sub.x. Me.sub.2 O.sub.3.(SiO.sub.2).sub.ywhere M is a cation of the valence n, exchangeable with calcium, x is a number from 0.7 to 1.5, Me is aluminum or boron, and y is a number from 0.8 to 6, and(B) from 30% to 80% by weight of at least two water-soluble alkali metal salts containing water of crystallization selected from the group consisting of tripolyphosphates, pyrophosphates, orthophosphates, sulfates, carbonates, metasilicates and borates; as well as the process of production of the same.