Hi folks, we are finally tackling our fireplace. Putting silver travertine stacked stone on the face, a big chunky mantel from old barn wood, and thought we were using these faux slate capstones for the raised hearth. But we aren’t loving how they are coming out when cut.

So, any suggestions on another material? Granite or something similar? Limestone? Formed concrete? We would like a dark grey material. I’m just confused and can’t find what I really want. Any help would be appreciated! Thank you!! Here’s a photo of our start.