Gold Occurrences in Connecticut

Gold has an early history in Connecticut where it was discovered and mined by the first governor ot the state, John Winthrop Jr. and one of his servants.  According to the story left by Winthrop they spent three weeks at Great Mountain near Cobalt, Connecticut mining, roasting, and assaying the ores from which they cast several gold rings.  Then he returned to his home in New London, Connecticut.  This was reported in the literary diary of Ezra Stiles the president of Yale University from 1778 to 1795.

Bedrock Geological Map of Connecticut
During the 1980s Prof. Anthony Philpotts and his geology class from the University of Connecticut discovered gold that assayed as high as 6 ounces per ton in the shaft of the old cobalt mine in Cobalt.  The discovery was made in the quartzite that overlies the cobalt deposit.  The assay work was done by the USGS.  The old time miners cut straight through the quartzite with no idea the gold was even present.

Dr. Philpotts got the credit for being the first discoverer of gold in Connecticut in modern times several years before that the author working with Newmont Mining that had a lab for assaying ores in Danbury, Connecticut found gold in the city of New Britain as an assessory mineral in a rock cut at the Columbus Avenue exit from Route 72.  The sample also contained several other metal sulfides including copper, lead, zinc and cadmium. The assay was performed at Newmont’s assay lab in Danbury.

Gold in Quartz, this is similar to a specimen that came from Leadmine Brook in Thomaston, Connecticut
Photo by Rob Lavinsky 

In the period starting about 1968 to present the author has sampled most of the streams in western Connecticut and is found virtually all of them contain gold. The quantity of gold discovered in the streams is small, and not enough to make a living at, but they do contain enough gold so you can see what it looks like.

Winthrop's alleged success has caused virtually every part of the state of Connecticut to be explored and dug into by some would-be prospector who is absolutely confident he would find a rich deposit of gold. One of the many traditions of course concerns a lost mine, but a very rich deposit of gold in the town of Ridgefield. On Mt. Carmel in Ridgefield there is an excavation that reportedly has had gold taken from it, and our Mt. Sanford in the same town there is a man who swears he has a gold mine in his backyard.

In at least two or three cases there have been companies formed that sold stock, but apparently no gold was ever found. In 1886 one prospector by the name of August Prehn picked up a piece of quartz on Mill Road in West Haven upon which he got an analysis that showed traces of gold. On the strength of this report Mr. Prehn’s son quit his job in Pittsburg and returned home where he organized a mining company that sank three shafts.. The stories differ about the amount of ore those taken from this mine, or even if any was taken at all. The only thing the townspeople can agree on was that after a short time all mining efforts at the mine were abandoned.

This is interesting because on the bedrock geological map of Connecticut this area is mapped as having contained greenstone that is considered by many geologists to be the source for hydrothermal gold deposits where the gold is leached from the stone. According to the New Haven register there was another gold rush that occurred in West Haven during the 1930s.

Most of the gold bearing rocks in Connecticut are discovered to the west of the Connecticut River an area in which there are abundant crystalline rock deposits many of which may be the source of gold. There is gold to be found in Connecticut, but it appears that any placer gold is going to be sparse. It is also obvious that although gold is present there probably isn't enough to make anyone rich, let alone make a living.