How to distinguish high-quality black granite from ordinary granite for precision measuring tools
I. Observe Color and Texture (Most Intuitive)High-quality Precision Grade Black Granite (Represted by Jinan Qing)Color: Pure black, uniform, matte black, not shinyGrain: Extremely fine, dense, particles almost invisible to the naked eyeTexture: No obious streaks, no white spots, no mica highlightsFracture: Fine fracture, like ink jade, not roughOrdinary Black GraniteColor: Graish, bluish, brownish, or mixed…