Connecticut Rocks and Minerals

Connecticut is small and the variety of rocks found there is small.

But Connecticut still offers great rockhounding.

A central lowland valley divides eastern and western Connecticut. This valley is cut by ridges of trap rock, while the eastern and western uplands are broken by mountains and valleys, exposing crystalline rocks containing gemstone materials. The trap rocks of the Connecticut valley yield agates, jaspers, amethyst and prehnite.

Connecticut is most well-known a one of the finest sources of almandine garnets, which became their state mineral in 1977. The garnets are primarily sourced from the Triassic age schists and gravels across a large area that was exposed by the Connecticut River. To collect some of the famous almandine garnets, be sure to look near Tolland County, Middlesex County, and Hammonasset Beach.

Also, there are specific parks you can visit to collect these beautiful red minerals, such as Eisenhower Park and Rocky Glen State Park.

The basalts exposed by the Connecticut River are also well known for prehnite. Torrington which is west of Hartford, is one of the best spots to find agates and prehnite crystals.

Other rocks and minerals that have been found in Connecticut include: fluorite, kunzite, moonstone, topaz, danburite, barite, beryl and aquamarine.

The marble quarries in Connecticut have been in operation since the 1700s, and many are still mining marble to this day. The type of marble that’s commonly found in Connecticut is called Stockbridge Limestone, and it’s mostly used for agricultural purposes.

Surprisingly, there are large amounts of high-quality serpentine all over Connecticut.

You can find staurolite in Glastonbury, Tolland, and Litchfield, Connecticut. One of the best places to find staurolite is Diamond Lake. In Butternut Creek in addition to staurolite, you may find pyrite and corundum.

Some tourmaline found in this state is called elbaite, and it displays different colors depending on the light. There are many quarries where you can find tourmaline in Connecticut, including Gillette Quarry, White Rocks Quarry, and Walden Gem Mine.

Smoky quartz, rose quartz, clear quartz crystals and amethyst have all been found in Connecticut.

Amethyst has been found in Orenaug Hills, Canton, Meriden, and New Haven. And near Collins Hill aquamarine, beryl, citrine, morganite, quartz, rose quartz, and tourmaline have all been found. Agates, jaspers, and geodes may be found near Durham and East Haven.

Long Island Sound, with its rich geological history and diverse marine ecosystem, presents an great opportunity for rockhounders. Exploring the shoreline and beaches along Long Island Sound can lead to discovering many different rocks, minerals, and even fossils.


Before venturing out-do some research on where and what you can collect. Remember you must have permission to collect on private property.

See my page on Rockhounding Rules for general information on the rules of collecting rocks on various lands.