2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/12050Clusters of galaxies allow a direct estimate of the metallicity and metal production yield on the largest scale so far. It is argued that cluster metallicity (about 1/3 solar) should be taken as representative of the low-z universe as a whole. There is now compelling evidence that the bulk of stars not only in cluster ellipticals but also in field ellipticals and bulges formed at high redshifts (z>~ 3). Since such stars account for at least 30% of the baryons now locked into stars, it is argued that at least 30% of stars and metals formed before z=~3, and correspondingly the metallicity of the universe at z=3 is predicted to be about 1/10 solar.8 pages, TeX file, 2 postscript figures To appear on: The Young Universe, ed. S. D'Odorico, A. Fontana, & E. Giallongo, ASP Conf. SerAstrophysicstext