THE COLONIAL PERIOD:
As soon as Europeans arrived in the New Netherlands, they began to search for mineral wealth, particularly precious metals. Initially, they traded for metal with the Native Americans and later, as homesteads and communities were established, the Europeans began to explore on their own. Gold and silver were never found in economic quantities but other metals were equally or more important for daily life. Iron was first extracted from “bog” deposits. These were small pockets of limonite (FeO(OH)) that were literally deposited in swamps. At the same time, limonite occurring in weathered pockets of rock in the Hudson Highlands was used for ore. These deposits soon proved to be too small and lean and further exploration revealed many deposits of magnetite (Fe3O4). This mineral became the iron ore of choice. The ore was reduced to metal in local refineries and used for cookware, tools, weapons and construction materials. Earliest iron mines of this period were located in Columbia and Orange Counties.
Lead and copper were also metals that the people of the colonial period sought. Galena (PbS) and chalcopyrite (CuFeS2) were mined in several counties in the Hudson Valley and in the Mid-Hudson region. The lead ore mineral galena also contains traces of silver and unsuccessful attempts were made to establish mines for the latter metal. In addition to metals, stone of several types was quarried for building purposes. Depending on the local geological resources, marble, limestone, sandstone were quarried for building stone. Further, clay deposits, which are common in the Hudson Valley, were mined for brick and rough pottery.