A bleaching clay product, a method of producing and a method of decolorizing an oil are disclosed. The bleaching clay product comprises attapulgite that has been thermally activated. The bleaching clay product may have a permeability in oil in the range of 0.04-3 darcy and may have a surface area of 45-140 m2/g. The method of producing such bleaching clay product may comprise thermally activating a material that includes attapulgite by heating the material at a temperature in the range of 300 to 900° C. The method of decolorizing may include contacting for a contact time an oil with the bleaching clay product that comprises attapulgite that has been thermally activated, and separating the bleaching clay product from the oil to recover a decolorized oil that has a lower red color than the oil had prior to the contacting.