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Marshfield: Jasper Rockhounding in Plymouth County, Massachusetts

Public accessBest spot1 mineralPlymouth County, MassachusettsUpdated July 2026
Mineral reported
1
Best months
March to December

Marshfield's beaches lie along the Massachusetts Bay jasper belt, where glacial gravels shed red and yellow jasper, epidote, and iron-rich feldspars onto the shore. A published mineralogical study of Marshfield beach and dune sand documents the epidote and feldspar content of this stretch of coast. The wide public beaches make it an easy, family-friendly surface hunt for waterworn jasper. Reported finds include jasper. Below: coordinates, access notes, nearby spots, and trip-planning links.

Plan your visit

Generally open to casual rockhounding

Nearest road
Porter Street
Postcode
02047
Get directionsView on Google Maps

Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.

Land & collecting status

Generally open to casual rockhounding

Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.

Access note: Collect loose cobbles on the public foreshore below the high-tide line at town beaches such as Rexhame and Green Harbor. Beach parking is resident-sticker only in summer, so visit off season or arrive on foot. Take only loose surface material and stay off the dune vegetation.

Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.

Best time to visit Marshfield

Comfortable months (45 to 90°F highs)

Best months: March to December. Typical highs run 84°F in midsummer and 41°F in midwinter, with winter lows near 22°F.

Climate normals: NOAA 1991-2020 monthlies, PLYMOUTH-KINGSTON station (9 mi away).

Today's weather

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The app shows live weather, recent rain, and a daily rockhounding score for Marshfield.

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Sources & verification

Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.

Found at Marshfield

Each name opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Nearby rockhounding spots

Other rockhounding spots within driving distance of Marshfield.

Across the state line from Marshfield

Marshfield is close enough to the Massachusetts border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Marshfield FAQ

Where is Marshfield?+
Marshfield is in Plymouth County, Massachusetts, at 42.11411, -70.66945. Nearest road: Porter Street.
What rocks and minerals can you find at Marshfield?+
Marshfield is reported to produce Jasper.
Is collecting allowed at Marshfield?+
Generally open to casual rockhounding. Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig. Always confirm current rules with the managing agency before a trip.
What tools should I bring to Marshfield?+
Most agate and jasper is surface float: bring a spray bottle, a pick or small shovel, and a sturdy bag. Wet stones show their banding and translucence.
When is the best time to visit Marshfield?+
The most comfortable months at Marshfield are March to December.
How do I get to Marshfield?+
Open the directions link to navigate to 42.11411, -70.66945 in Google Maps. The nearest road is Porter Street.

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