True slate roof tiles are made entirely of natural stone and include no additives. Slate roofing, like real granite countertops, is extracted from the soil. Slate may be distinguished by the way light strikes it at a specific angle. This is due to the high mica concentration of slate tile. The microscopic structure of slate is composed mainly of silicon dioxide (silica) and aluminum oxide. It has an extremely dense crystalline structure that makes it very hardy; most types of weathering cause little more than color changes to the surface. Slate was originally used as roofing material because it is easy to work with and durable. It can also add value to your home! Unfortunately, slate is also heavy so it's not always the best choice for colder climates where it can lead to leakage issues if not installed by a professional roofer. However, if you live in a region that gets plenty of sunlight exposure, then a slate roof is a great option!