Abstract: A heavily filled bismuth compound composite having a polymer matrix and a bismuth compound therein. The bismuth compound may be bismuth oxide, or other bismuth compounds. The polymer may be any of a very wide range of materials or combinations thereof. Binder, secondary fillers or other third components may be added. By means of use of various bismuth compounds, polymers, and third components, the physical, radiological and electrical properties of the finished products may be tailored to achieve desired properties. In addition, the invention teaches that radiation shielding, insulators, and combined radiation shield/insulators may be fashioned from the composite. A wide range of production methods may be employed, including but not limited to liquid resin casting.