Silver has been related to the mining activity in Connecticut. Probably, the first of the early colonists to turn his attention to the mineral wealth of this state in particular was Governor Winthrop who interested himself to a considerable extent in examining the metallic deposits of the Connecticut Valley, especially in the vicinity of Haddam and Middletown during the period 1650 to 1660. Considerable galena was found in the state with important amounts of silver, probably, the most important silver-lead mine was near Middletown. It is supposed that this mine was operated many years prior to the revolutionary war.
Although the argentiferous lead mines of Connecticut and especially those of Middletown are famous as being the first to receive attention in the United States, practically no ore of commercial importance has been obtained from them. Galena was abundant in the state; the more important locations were Monroe, Plymouth and Middletown. The Lane mine at Monroe yielded rich argentiferous galena disseminated in a bed of quartz,, but in limited quantities. Probably the most important geology is that at Middletown. The galena occurred in a thin vein of quartz in mica-slate having a thickness of 10 to 20 inches. The ore was associated with sphalerite pyrite and rarely chalcopyrite. Aside from the quartz, mica-slate occurred as a vein filling.
During the 1980s, Anthony Philpotts and his class of geologists discovered one of the richest gold lodes ever discovered in North America. This was in an area of Silurian aged quartzite that was assayed by chemists of the United States Geological Survey, USGS. The samples were characterized by the presence of quartzite and reported from 1.5 to 6 ounces of gold per ton of the quartzite. This has been the first documented occurrence of gold in Connecticut and was significant because the northeastern region has been overlooked in the past few decades as far as metallic resources are concerned.