Using precisely cut, smooth-finish tiles and spacing them evenly on a fireplace surround can achieve a sleek and sophisticated look, according to Standout-Fireplace-Designs.com, an online fireplace planning and design service. When you opt for this look, you can place the tiles in vertical or horizontal rows or in a diamond pattern. The tiles can be uniform in size or a mixture of sizes--the key is to space them evenly.
According to Vermont Structural Slate, "most fireplace surrounds are custom-fabricated from large stones." Using only a few large slate stones or slabs can create a modern angular look when the stones are laid straight vertically, horizontally or both. In contrast, you can achieve a rustic look by laying large irregular blocks and slabs in a random pattern.
Stacking slate bricks or tiles creates a textured, compact look that can be rustic or modern. In this style, mortar lines are thin, so that the finished look showcases the brick edges, rather than the mortar. Slate bricks have thick edges and tend to look rustic when stacked. Slate tiles have very thin edges; therefore, when stacked, slate tiles create a structured-looking surround that fits well with contemporary interiors and is reminiscent of 1950's era modernism.