Massachusetts Rock and Minerals

Massachusetts, though small, has great rocks and minerals found there.

Massachusetts is divided into two geological provinces by the Connecticut River. East of the river, the land falls, with a few elevations, to the ocean, and the underlying rock is contorted metamorphic shist. West of the river is the Appalachian Mountains. At one time, the state was actually covered by 5 glacial lobes. When they melted, they created glacial lakes dotted across the state and the mass volume of water undercut much of the glacial deposit in the Connecticut River valley. Therefore, most of the gem quality rocks are found within the Connecticut River valley or just east of it, and in the Essex County area in the extreme northeast part of the state.

Rhodonite was named the state’s official gemstone in 1979. Rhodonite can be found in Plainfield, in Hampshire County, where you can also find spessartine garnet, magnetite, hematite, and chalcopyrite. The Betts Mine, in Plainfield, Massachusetts, is an old manganese mine. It is well-known for producing rhodonite and rhodochrosite, as well as cummingtonite, almandine–spessartine garnet, pyrite, pyrrhotite, and chalcopyrite. I have heard that this mine is open to collectors as a Pay to Dig.

The best places to go rockhounding in Massachusetts is in the many quarries. At the Hampden Quarry in West Springfield, you can find Datolite, rare Babingtonite, and Prehnite. At the PJ Keating Quarry in Dracut, in Middlesex County, quartz crystals, opal, kyanite, and diopside, have been found. The Bolton Lime Quarry in Worcester County has large pink scapolite crystals, and on the west side of Rollstone Hill where you can find a pegmatite which contains beryl.

There are many mines and quarries in the Hampden County area are that have produced minerals like beryl, galena, amethyst, and prehnite, but they may be difficult to gain access to. In Hampden County in the area around Chester, there are several old mines and outcrops, collectively known as the Chester Emery Mines. The presence of iron ore deposits at Chester was known as early as 1835-1841. The first emery discovered in America was found at the Chester mines. Beryl, including blue aquamarine and green emerald, is often found in granite pegmatites throughout the state of Massachusetts. But the best place to find high quality beryl is in Hampden County.

Tourmaline is found in the areas around Worcester and Berkshire counties. Garnets, in both red and green and some of them gem quality, are found in various locations in Massachusetts, particularly in the areas surrounding the Berkshire Hills.

In the Connecticut River Valley, collectors can find plant fossils, fish fossils, and even dinosaur footprints that date back millions of years.

Varieties of quartz, such as amethyst, smoky quartz, and clear quartz, also can be found in various locations throughout the state, including granite pegmatites and hydrothermal veins.

In Essex County, in the northwest part of Massachusetts, you can find sodalite, chalcopyrite, galena, and jaspers. There are 10 mines identified in Essex County. The most commonly listed commodities in these mines are silver, gold, and iron.

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.