Synthetic mineral immobilization technology is an approach for the treatment of heavy-metal concentrates, Although the notion of using synthetic mineral analogs for the stabilization and consolidation of nuclear waste has been discussed for more than 40 years, its application to inorganic hazardous waste, in general, is only now being realized. The advantage of this technology is that high-waste-loaded and high-density waste forms can be fabricated while maintaining excellent chemical durability. These properties translate into considerable savings during transport and disposal.