Profile of One of our Sources
North Country Unfading Black Slate, produced in Canada, is quarried from the purest deposits of the Ordovician geological era by Glendyne Quarries Inc. www.glendyne.com. Its composition and smooth surface is exceptionally durable and its unrivalled quality makes it sought after internationally. Discovered during the construction of the Trans-Canada Railway at the turn of the 20th century, North Country Unfading Black Slate is quarried using state-of-the art cutting and sorting techniques. The highly skilled craftsmen who finish the slates produce lasting and elegant coverings for the world's most prestigious buildings.

North Country Unfading Black Slate withstands the rigors of time and is recognized and appreciated for its quality by roofing professionals.

How Slate was Formed
The origins of slate go back approximately half a billion years to sediments formed at the bottom of the sea. These mixtures of clay and mud hardened into shale over hundreds of millions of years until tectonic pressures folded the layers into mountains. Shearing forces caused the sedimentary rock to be mixed with calcite, mica, quartz, volcanic ash, and other minerals under enormous heat and pressure, which melted and recrystallized the mixture into slate. The various colors of slate depend on the presence and amounts of graphite and metallic oxides such as iron and titanium.

A Brief History of Slate Quarrying in North America
Slate roofing is known to have been used as far back as the mid-seventeenth century in the colonial United States. Building ordinances of the era in New York and Boston recommended slate and tile roofing as a means of fireproofing. Originally, the slate had to be imported from Wales, but North American slate quarries opened increasingly after the American Civil War, until by the close of the nineteenth century over 200 slate quarries were in production in the United States alone.