showed that quarries in the town of Slatington alone had shipped 81,402 squares of roofing slates (over 8 million square feet) as well as 40,486 cases of school slates and 243 cases of blackboards. The Slate Valley (the district of Granville, New York) is well known for its slate. Slate was quarried in 1839 at Fair Haven, Vermont. An influx of immigrants from the North Wales slate quarrying communities saw a boom in slate production that peaked in the latter half of the 19th century. The slate of the region comes in a variety of colors, notably green, gray, black and red. Some production continued in 2003 with 23 operating full-time mines employing 348 people. Additionally, one of the oldest quarries in America continues to quarry slate in Buckingham County, Virginia. Their trademark Buckingham Slate has been continually quarried since the 18th century and has a distinct, unfading blue/black color and Mica sheen. Buckingham Slate is used on many Federal buildings in the Washington, D.C. area. Large scale slate quarrying also took place around the town of Monson, Maine where an extensive series of quarries flourished from the 1860s onwards. A small scale quarrying and dressing operation continues in Monson into the 21st century. Slate is also found in the Arctic and was used by the Inuit to make the blades for ulus. Slate industry in Brazil 95% of the slate extraction in Brazil comes from Minas Gerais. Slate from this region is formed differently from traditional slate areas such as Galicia. Such products are sedimentary rocks that have split along their original bedding plane, whereas true slate has been subjected to metamorphism and does not split along bedding, but rather along planes associated with the realignment of minerals during metamorphism. This realignment, known as ‘schistosity’, bears no relationship to the original horizontal bedding planes . The independent Fundación Centro Tecnológico de la Pizarra’s report into the ’Technical properties of Bambui Slate from the State of Minas Gerais (Brazil) to ascertain its compliance with the Standard EN12326’ describes how certain products originating from Brazil on sale in the UK, are not entitled to bear the CE mark. Because such Brazilian products display higher water absorption indexes than those from other areas such as Galicia, this makes them less suitable for use as roofing tiles since the study showed a significant loss of strength when subject to thawing and freezing. See