The invention provides inter alia a mineral complex comprising about 40 wt. % to about 60 wt. % SiO2, about 6 wt. % to about 16 wt. % Fe2O3, about 4 wt. % to about 12 wt. %. CaO, about 2 wt. % to about 8 wt. % MgO, wherein at least 85% of the mineral complex has a particle size of about 10 to about 6000 mesh, related compositions and methods for their use, including for growth medium augmentation and remediation.
