The granite in the
Wicklow Mountains, wherein Ballyknockan sits, is of
Devonian age dating to around 400 million years ago Granite has also been exploited on the island of Ireland in counties
Galway,
Donegal and
Down. According to Patrick Wyse Jackson, curator of the Geological Museum in Trinity College, close examination of Ballknockan granite reveals its constituent minerals, which include: "...pale, glassy
quartz, milky
feldspars, and black and silvery
micas. The Ballyknockan variety is medium- to coarse-grained, with interlocking crystals some three to four
millimetres in size. Apart from the minerals mentioned above, the granite also contains some
chlorite". The wider Dublin area was exploited for its granite long before the 1820s when the Ballyknockan quarries were established, and it is known that granite quarrying took place at
Dalkey quarry, close to Dublin city, from 1680. Granite was commonly known as "firestone" until the late eighteenth century; not from its classification as an
igneous rock (which at this stage was still unknown), but rather from its initial usage as a material from which to make
fire grates and
chimney pieces owing to its heat-resistant properties. Prior to 1720, calp limestone was the main stone building material used in Dublin, and was quarried locally in the suburbs of
Palmerstown,
Kimmage,
Rathgar and
Donnybrook (where a
Dublin Bus depot has existed since 1952). After this date, imported limestones, sandstones and granites began to replace the calp as they became more popular. The nearest granite sources to Dublin were the quarries of south
County Dublin and north-west
County Wicklow, which, however close, still required the costly and labour-intensive transport of stone to the city, especially when via
overland haulage (as was the only option for Ballyknockan haulers). The operation of moving the materials to the building sites of Dublin required raising large blocks of
hewn stone (in blocks of up to a quarter-
ton) onto a wooden blockwheel
cart (aka the 'Irish carr') using hand-powered
lifting tackle. According to Hussey, the Irish carr was "the standard transport vehicle used in Ireland until the early nineteenth century". The eighteenth century, "probably Dublin's most prosperous period" according to Wyse Jackson, saw the erection of many of Dublin's most important public buildings which were built of calp limestone rubble walls and "
faced with either Leinster granite or Portland stone" imported from England. Granite from the Wicklow and Dublin Mountains, and limestone from the immediate hinterland, came to be the primary stones used in the construction of Dublin city, and can be recognised as "characteristic to Dublin" in the same way that
basalt from
County Antrim and granite from the
Mourne Mountains came to typify
Belfast's urban landscape.
Local quarrying in the 1700s mountain in the distance According to Wyse Jackson and Caulfield, "Granite was reportedly first quarried in west Wicklow in the early 1700s from several openings at Baltyboys near Blessington, and from 1740 in more significant volumes at Woodend and Threecastles nearby and then from
Golden Hill" near the village of
Manor Kilbride. According to Wyse Jackson and Caulfield, the ability to quarry granite in considerable volume was delayed in Ireland until the mid-1700s due to technological constraints. Stones from the west Wicklow sources, especially Golden Hill, were used in the construction of many important Dublin buildings, all constructed in the 1700s. A detailed map of the Blessington area produced by Jacob Neville in 1760 shows quarries at Golden Hill and Oldcourt, but no quarrying at Ballyknockan. At that stage there was not even a road to the village, although by 1771 it is known that a small community were living onsite in a
clachan, or hamlet, as a list of occupying families exists for that year. ==19th century==