Delaware Minerals Industry

Minerals Industry Report for Delaware View/Print/Download the complete report in PDF format In 2007, Delaware’s nonfuel raw mineral production was valued at $24.7 million, based upon annual U.S. Geological Survey (USGS) data. This was an increase of 10% from that of 2006, which followed a 12% increase from 2005 to 2006. Because production data for magnesium compounds and crushed stone were withheld (company proprietary data), the State’s actual annual total values are significantly higher than those listed in table 1.  In 2007, Delaware’s leading nonfuel mineral continued to be construction sand and gravel with its production up by nearly 20%; the mineral commodity’s production value rose less so, by slightly more than 10%, because of an overall decrease in its average annual unit value (table 1). This was followed by magnesium compounds, the value of which was a significant portion of the State’s actual total value. Modest decreases took place in the production and related value of magnesium compounds production. In 2007, Delaware continued to rank fourth of fi ve States in the quantities of magnesium compounds produced. Magnesium compounds, extracted from seawater close to the mouth of the Delaware Bay, near Lewes, Sussex County, were used to manufacture chemical and pharmaceutical products. Crushed stone (classifi ed as limestone for statistical purposes) from various out-of-State sources was processed through the sales yards of Tilcon Delaware, Inc. in Kent, New Castle, and Sussex Counties. The last crushed stone production from a Delaware quarry was reported to the U.S. Bureau of Mines in 1968; the State’s only stone producer ceased operations in New Castle County near Wilmington at the end of that year (Gustavson, 1971, p. 204). Gabbro (classified as granite for statistical purposes) was quarried and then crushed and sized as a concrete aggregate or as stone sand, while a small quantity was sold as riprap. During the previous several years, the State’s crushed stone needs progressively had been fulfilled by purchases of stone from sources in Maryland and Pennsylvania (Gustavson, 1970, p. 196). All gemstones production was from that of hobbyists.