Abstract: A method of providing silver on a calcium carbonate material having fine pores, such as coral sand, oyster shells, and crab shells, including (a) contacting a calcium carbonate material with an aqueous solution of silver nitrate for a time effective for the silver nitrate to react with the calcium carbonate to form silver carbonate on the surface of the calcium carbonate material; (b) dewatering the calcium carbonate material after step (a); and (c) treating the calcium carbonate material after step (b) in an aqueous solution containing from 5 to 15 weight % of a reducing agent selected from the group consisting of ascorbic acid, a derivative of ascorbic acid, erythrobic acid, and a derivative of erythrobic acid to reduce the silver carbonate on the surface of the calcium carbonate to silver. Preferably contacting is by injection of an upward stream of the aqueous solution of silver nitrate through a layer of the calcium carbonate material.