Technical DataQuality, Durability, Resistance to Frost, Water Absorption, Compressive Strength & More… Harvest Sandstone. A dual toned sandstone with subtle earthy colours Technical Port Sandstone. An even flat bed sandstone with three main colours ranging from light greens, browns to light blues giving an overall even natural appearance. Technical Grey Limestone. A strong, hard grey limestone with small amounts of brown naturally occuring in the stone Technical Blue Limestone. A strong hard blue limestone with a natural white fossil present in the stone Technical Blue Sandstone. Typically dark blue with some bronze hints Technical