Effect of Surface Finish on Roughness, Color, and Gloss of Ornamental Granites

Abstract

The effects of four of the most common types of surface finish on the appearance of five varieties of ornamental granite, all widely used in building construction and selected for their different colors, were analyzed by means of roughness, color, and gloss measurements. The results demonstrated that different surface finishes produce differences in color, especially in the lightness parameter (L* ), and that the magnitude of these differences depends on the color of the ornamental granite and is greatest in dark colored rocks. However, the variation in the color parameters with the different surface finishes did not depend on roughness, and no general conclusions could be drawn regarding the influence of the roughness on the color of ornamental granite. Gloss values were affected by the color of the ornamental granite, but in a different way for smooth and rough surfaces. Variation in gloss also depended on the mineral composition of the rock. Gloss and roughness were inversely related, but only within the range of low roughness values. In addition, the color gamut of the studied ornamental granites was defined within the CIELAB color space. These results will contribute to providing a standardized, objective method of characterizing the color of granite that will be useful for different workers in the field of building construction.