Slate with its natural colors, varied multicolored patterns and textures provide this stone with a distinctive appearance.
Sealing to minimize staining… Colored slates benefit from color enhancing treatments designed to magnify and protect the natural colors. When dealing with colored slates there are two distinct types, Fading and Unfading. After a period of exposure to the environment (sun/water) fading slates will alter generally to a lighter color. The unfading varieties will retain their true colors. Multi-colored slates used for flooring will undergo color changes in abrasive foot-traffic areas. The colors in these varieties of slates are in thin bedded layers… Some slates will dust for awhile after installation on floors as loose scale is removed by foot traffic. This will stop as the surface settles in, usually in a few weeks… *The majority of the multi-colored slates are what are termed “clay slates” and generally have a high content of clay minerals and are geologically classed as a low-ranked slates, those in which the metamorphic process was halted at a very early stage. These slates weather poorly in exterior wet/humid climates.
Slate is a fine grained metamorphic stone formed from clay mud; composed of sediments of decomposed stone and organic matter that has been hardened by heat and pressure. Since the geological process varies greatly, slates range quite a bit in hardness and porosity.
Commercially “Slate” has become a trade term. This has lead to the classifying of some stone types as slate. An example of this is using “Shale” that’s been commercially classified as “slate”, (most states where a shale before the metamorphic process). Shale weathers poorly and very poorly in wet/humid climates. Soon after installation in exterior applications this stone crumbles, spalls excessively and can literally turn to powder.
It’s important to judge the performance characteristics of different slates individually and not assume that all slates are alike.
Slate types & sizes
