Lowell is a mosaic-style natural stone veneer subject to heavy color variation.  The stone can range from a monochromatic grey to grey with heavy tans and browns.  The colors can vary from one production run to the next, therefore, it is important to check with us ahead of time to see the current colors.  The stones all come from the same quarry as well as the general area within the quarry, but the colorfulness is determined by how tightly packed the layers of stone are within the ground.  Where the layers are tight, the stone comes out in semi-consistent grey tones because rainwater carrying minerals could not penetrate between the layers.  Where the layers are loose, the groundwater settled between the layers and stained the stone with minerals over the centuries which gives the pieces the rich earth tones.  Lowell is a split-back product and has not been sawn on the back with a diamond blade. This has no impact on installation or final appearance.