Schisty

1884, Reports from Her Majesty's Consuls on the Manufactures, Commerce, &c. of Their Consular Districts, Parts 1-5, Harrison & Sons, p. 114, https://books.google.ca/books?id=p73NAAAAMAAJ&printsec=frontcover&source=gbs_atb#v=onepage&q&f=false The Upper Douro wine began to fetch great prices, and this was the signal for the cultivation, bit by bit, of the whole region as far as the schisty soil, which gave the good wine, reached.

1969, Edwin S. Deflethsen, "Colonial Gravestones and Demography" reprinted in Maris A. Vinovskis (ed.), Studies in American Historical Demography: Studies in Population, p. 211, https://books.google.ca/books?id=5XOLBQAAQBAJ&printsec=frontcover#v=onepage&q&f=false Black and reddish slate stones even of the seventeenth century have borne the climate well and are still easily legible, while some of the more schisty sorts of greenish slate used in Plymouth County, Massachusetts, have survived poorly and are difficult to read.

2007, Tom Cannavan, wine-pages.com https://web.archive.org/web/20160409134423/http://wine-pages.com/tasting-articles/june-2008-yali-cook-wines-domaine-de-fondra-che-willi-opitz/ It has a gorgeous, pure, strawberry and rose-hip nose, with some plump sultana notes and a certain mineral quality that is quite schisty and earthy.

At times he loved it best in Wet Season — when the creeks were running and the swamps were full — when the multi-coloured schisty rocks split golden waterfalls — […]