This section is from the book "Modern Buildings, Their Planning, Construction And Equipment Vol5", by G. A. T. Middleton. Also available from Amazon: Modern Buildings.
(Contributed by R. J. Haddon, F.R.V.I.A., F.S.A.I.A.)
Australia may be said to be rich in good building materials, none of the least of which are her varied and widely spread deposits of good workable building stone.
Practically the whole area of Sydney, with its hills around the harbour, is of rich sandstone formation. These Hawkesbury freestone deposits, as they are called, extend for many miles around, and are extensively worked for building purposes.
This permanent supply of easily quarried material has in a marked degree influenced the architecture of this fine city and its picturesque suburbs, where the stone for the building is often quarried from the site itself; and the formation of the country being for the most part hilly, this is scarcely a defect to a building site, rather in many cases does it prove of advantage, for the designer may not only consider the mass of the building, but may modify the structure of the hilly approaches.
The Pyrmont quarries are the most famous in Sydney, and have supplied stone for many years for some of the largest city buildings all over the continent.
The nature of this stone is medium in structure, and may be compared with some of the well-known Scotch freestones, such as one sees in Glasgow and other leading cities. Worked at moderate cost, and being of a warm buff colour that harmonises with the red brickwork so universally seen in Australia, and in tune with her clear atmosphere and blue skies, it has proved one of the most reliable materials for structural and decorative purposes. This stone can be obtained in blocks of great size for columns, landings, etc., and lends itself readily to mouldings and carvings, the method of dressing adopted being as follows - Bolstered and chiselled beds and joints; Rubbed, tooled, or quarry-faced ashlar for general work; Rubble for infilling.
To the north and west of Melbourne stretches the great basalt country that has given Melbourne and her surrounding towns a sound hard bluestone. This is largely used for all purposes where special strength combined with hardness is required.
This stone is dark blue in colour, slightly honeycombed, and is obtainable in large sizes, the stones of largest dimensions and finest texture being produced from the Lethbridge quarries, about sixty miles from the capital city. A bluestone of a softer nature, much used for structural works (and sometimes built in colour contrast with imported freestones), is obtained from Malmesbury.
This material was largely used in public buildings in the early days, but has now been superseded to a very great extent by other materials on account of its sombre colour and excessive cost. Bluestone is, however, almost invariably used for window sills, thresholds, and stone stairs, forming in this way a most permanent and satisfactory material.
Of granite there is an unlimited supply, of a fine grey variety, obtained from Harcourt, about eighty miles north of Melbourne. This stone is seen in some of the largest city buildings, both in polished column, pilaster, and plinth work, as well as in fine patent axed ashlar. A red variety, also used, is obtainable from Gabo Island.
Stawell freestone should also be specially mentioned. This is a fine white sandstone, hard in working, but capable of very fine finish, and admirably suited for such buildings as the Victorian Parliament Houses, which have been erected of it. It is rich in silica, and the hardness of its working renders it very expensive for private use.
Other freestones include the Wawin Ponds free limestone and Barrabool Hills free sandstone. The former, of a warm buff colour, is largely used for dressings, and the latter, which is of a greenish colour, for general wall facings. This combination may be seen in the Melbourne Anglican Cathedral designed by the late Mr. Butterfield, and also in Ormond College at the University, at the Melbourne Technical College, and other important buildings.
Queensland has produced good workable freestones, though the quarries for the most part are limited in extent and the best beds soon exhausted. The expense of carriage has also confined its use to the important buildings only, the general run of building being of brick.
Australian Methods - Masonry and Brickwork 189
In Brisbane the freestone most generally used is from the Helidon quarries, some sixty-five miles from the city. This stone is of fine texture, easily worked and good in colour, and has been used in the public offices and as rubbed ashlar in the Brisbane Railway Station. Yan Gan is another freestone now coming into use in the New Lands Office.
Porphyry is also quarried near Brisbane, and is used in foundations, base courses, plinths, and in coursed work or squared rubble. Of volcanic origin, it is hard and durable, and can be dressed with chisel or axed. Grey granite is also used.
Tasmania produces good workable stones at moderate cost for general building, freestone from Kangaroo Point being in the opinion of some authorities the best freestone found in Australia. Analysis has given as much as 27.75 per cent. of silica. This stone has been somewhat extensively exported to the mainland, and is seen to advantage in the great Law Courts of Melbourne. •
South Australia has also a good stone supply, and many of the houses of Adelaide are built of stone.
The Mintaro slate from this part of Australia is one of the finest slates in the world, being even in colour and dense in texture, while it can be brought into the building in almost any size up to 10 feet square. It is therefore largely used for lavatory and general slab work, as also for curbing, paving, etc.
Fine coloured marbles are now also reaching the building markets, and some excellent specimens from New South Wales quarries are to be seen in city buildings.
West Australian Stone - In and around the Westralian capital city of Perth, Cottisloe shell limestone is much used, while a variety of superior quality is worked in Rottnest, an adjacent island.
Good granites are also obtained in various parts of the State, while for goldfields work the Kanowna stone (a kind of decomposed granite) has been used in the Kalgoorlie public buildings and around the general district of Coolgardie.
Of imported stones, large quantities of Omaru soft white limestone have been used all over Australia, being easily worked and specially adapted for carving, and having the quality of hardening upon exposure. This stone has been extensively used in ecclesiastical work, especially in interiors, as in the high altar of St. Mary's R.C. Cathedral, Sydney, designed by the late Mr. W. W. Wardell, F.R.I.B.A.
Omaru stone is sawn into shape with hand saws, and steel dragged to fair surfaces.
Another New Zealand stone of much finer quality is a white limestone from Mount Somlis quarries, in Canterbury, New Zealand. From the same locality is also obtained a pink limestone which, in combination with the white stone, has been used with fine effect in one of the best designed city buildings in Australia in the perpendicular Gothic manner - Empire Buildings, Collins Street, Melbourne - subsequently altered and converted into insurance offices.