Hobart's General Post Office in about 1900 (ALMFA, SLT)
Tasmanian sandstones have been quarried and used to build many private and public buildings. Commonly, a small quarry was developed close to the chosen house site, such as the one next to Government House which has been included in the garden as a pond. Sandstone has been shipped interstate, principally to Victoria, and used to build public buildings.
On the whole, Tasmanian sandstones do not weather particularly well as most contain clay minerals such as smectite, illite and kaolinite. Dolerite or bluestone is a more durable rock, but correspondingly harder to quarry. Tertiary aged basalt, from near Miena ('black granite') has been prized for use by monumental masons in shaping tombstones. Granites suitable for use as dimension stone are quite common in north-eastern Tasmania, although most of the granites are of fairly 'ordinary' colouring. Red granite has been quarried near Coles Bay and from a location near Trial Harbour.
The term 'marble' is used by stonemasons to refer to almost any carbonate rock which polishes well. Precambrian magnesite has been promoted as 'Tasmatine Marble', although there is no large-scale extraction of this material. Slate for flooring has been quarried from Back Creek and Lefroy.