Many of the older buildings are of a brown sandstone, quarried in or near the city.
Granite and limestone are quarried in the vicinity.
Limestone quarried in the same year was worth $124,690; and sandstone was valued at $39,216.
As quarried or mined free sulphur is always contaminated with limestone, gypsum, clay, &c.; the principle underlying its extraction from these impurities is one of simple liquation, i.e.
A thriving export trade is carried on in agricultural produce, condensed milk is manufactured, and slate is extensively quarried in the neighbourhood, while some coal is exported from the neighbouring fields.