The present invention relates generally to abrasive stone pads for use in processing workpiece surfaces. The abrasive stones generally are produced by combining a phenolic resin mixture with a diluent and then injecting microballoon structures into the resin/diluent mixture to create a porous solution. The diluent is initially ball-milled with an abrasive in a tumbler to eliminate the agglomerates and is then added to a resin monomer. A suitable catalyst is added to the mixture to create a chemical reaction, further increasing the porocity of the substance. The mixture is poured into molds and through a filter of frit plate to remove excess resin and diluent. Finally, the mixture is cured, creating abrasive stones having a uniform surface and bulk structure with a uniform hardness, suitable for workpiece grinding.