Assertion: slate | /r/HasProperty | mined
Facets:
Source sentences:
text: The lime which was in the slate, when the slate was mined, had not caused deterioration because the slates were protected from sunlight.
text: It is a natural rock that is mined and cut to become a form of 'shingle' (a thin, tapered piece of material used as a roof and wall covering).
text: The slate industry grew slowly until the early 18th century, then expanded rapidly until the late 19th century, at which time the most important slate producing areas were in northwest Wales, including the Penrhyn Quarry near Bethesda, the Dinorwic Quarry near Llanberis, the Nantlle Valley quarries, and Blaenau Ffestiniog, where the slate was mined rather than quarried.