Important Color Information

A common misconception associated with the nomenclature of describing slate is the fact that frequently the term weathering and fading are erroneously interchanged. Slates are classified as fading or unfading solely according to color permanence. Fading is characterized by a chalk-ashen residue that lessens the slates aesthetic beauty. The term unfading often refers to Blue-Black and Blue- Gray slates.

The term weathering refers to colored slates. While colored slates do not fade, some will experience some color change. The weathering of slate is induced by the oxidation of minerals as they are exposed to the elements. The weathering process slowly changes the color of the individual slate. Weathering slates will often exhibit changes that result in the color gradually turning to buff, brown, grays, or tan shades.

Colored slates can be classified as one of three types. The classification is based upon the extent to which the slates molt. The term weathering refers to slates that will exhibit the largest number of individual pieces that will transform from the original color to an earth tone. Slates deemed non-weathering would exhibit the least amount of color change. As the name would imply, semi-weathering slates are a combination of the two aforementioned types. Some of these slates will exhibit color change while others remain their original shade. The percentage of semi weathering slates that will experience color change is variable depending upon the location in the quarry from which the slate is extracted.