1. A magnetorheological material comprising an aqueous carrier fluid, magnetic- responsive particles having average diameters of 0.10 to lOOOμm and at least one additive selected from bentonite and hectorite.
2. The material of claim 1 further comprising 0.1 to 5 volume percent of a water- miscible organic solvent, based on the volume of the aqueous carrier fluid.
3. The material of claim 1 wherein the magnetic-responsive particle is selected from iron, iron alloys, iron oxides, iron nitride, iron carbide, carbonyl iron, nickel, cobalt, chromium dioxide, stainless steel and silicon steel.
4. The material of claim 1 wherein the additive comprises a synthetic hectorite.
5. The material of claim 1 wherein the amount of magnetic-responsive particles is 50 to 90 percent by weight of the composition.
6. The material of claim 1 wherein the amount of aqueous carrier fluid is 10 to 50 percent by weight of the composition.
7. The material of claim 1 wherein the amount of the additive is 0.1 to 10 percent by weight of the composition.
8. The material of claim 7 wherein the additive comprises a synthetic hectorite.
9. The material of claim 1 wherein the magnetic-responsive particles have average diameters of greater than 1.0 μm.
10. A magnetorheological fluid wherein all the ingredients are inorganic.