Valentia Slate Quarry 
Heritage Site(s)
- County:
- Kerry
- Townland:
- Dohilla
- Status:
- Active
- Primary Rock Type:
- Slate
- Start Date:
- 1816
- Owner/Operator(s):
- 1816-1825, 1831-1839: Knight of Kerry; 1825-1831: Irish Mining Company; 1839-1877: Blackburn; 1839-1877: Fitzgerald, Knight of Kerry, Peter
Notes:
A slate quarry, on the eastern slopes of Geokaun in the townland of Dohilla, was opened by the Knight of Kerry in 1816. Throughout the nineteenth century it was worked by the Knight of Kerry, the Irish Mining Company and the Valentia Flag Company who developed the export trade. The slate is difficult to split and therefore not suitable for roofing. Valentia slate was only used locally for roofing purposes, while slate raised at Coole and on the west side of Beginish in Valentia Harbour was preferred in the region.
The slate at the Valentia quarry was raised in large, durable, attractive slabs, and these were exported to London and America. Slabs as large as 20 feet long were exported to London. Valentia flags were chiefly used in London for skirting, cisterns, paving, dressers and tables. Export of Valentia continued successfully through the mid-1800s, until Welsh slabs entered the market. Although the Welsh slabs were inferior, softer and smaller, they were lower prices and more easily sawn and planed.
Valentia slabs cost from 35s. to 55s. per ton, depending on size. There are three slate beds in the Valentia quarry. The upper 9 feet thick bed produced the finest slabs, which were approx. 14 feet long by variable widths. The middle 16 feet thick bed is slightly softer and did not produce economically viable slabs due to diagonal jointing. However, it split more easily than the upper or lower beds and therefore yielded roofing slates for local use. The lower 14 feet thick bed was inferior for slabs than the upper bed, but better than the middle one, having less diagonal joints, so in certain areas decent-sized slabs could be raised.
The raised slabs were moved a short distance within the quarry, planed, and sawn into lengths of 4 - 5 feet, or as required. They were then transported to the saw mills for division into 1/2, 3/4 or 1 inch slabs. In 1845 the depth of overburden was approx. 50 feet, below which the quarry had been worked about 60 feet.