Plainfield: Ankerite & Garnet Rockhounding in Hampshire County, Massachusetts

Updated June 2026

Plainfield is a mapped rockhounding spot in Hampshire County, Massachusetts. Reported finds include ankerite, garnet, quartz, rhodochrosite, rhodonite. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Hampshire County
State: Massachusetts
Postcode: 01070
Coordinates: 42.53435, -72.92483

Geology at Plainfield

This spot sits on Hawley Formation, mapped as amphibolite, greenstone, and schist that formed roughly 440 to 425 million years ago. Metamorphic terrain like this typically carries quartz veins and sweats, and weathered crystals tend to end up in the soils and streams below.

Mapped unit: Hawley Formation
Age: 440–425 Ma (Llandovery to Wenlock)
Rock types: amphibolite, greenstone, and schist
Elevation: 1,530 ft

Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.

Best time to visit Plainfield

Best months: April to November. Typical highs run 75°F in midsummer and 29°F in midwinter, with winter lows near 10°F.

Climate normals: NOAA 1991-2020 monthlies, E HAWLEY station (4 mi away).

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.

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.

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.

Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.

Found at Plainfield

Each chip 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 Plainfield.

Across the state line from Plainfield

Plainfield 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.

Plainfield FAQ

Where is Plainfield?+

Plainfield is in Hampshire County, Massachusetts, at 42.53435, -72.92483.

What rocks and minerals can you find at Plainfield?+

Plainfield is reported to produce Ankerite, Garnet, Quartz, Rhodochrosite, Rhodonite.

Is collecting allowed at Plainfield?+

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 Plainfield?+

A rock hammer, a small pry bar, gloves, and safety glasses cover most crystal ground. A screen helps in loose pocket soil, and newspaper protects points on the way out.

When is the best time to visit Plainfield?+

The most comfortable months at Plainfield are April to November.

How do I get to Plainfield?+

Open the directions link to navigate to 42.53435, -72.92483 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Massachusetts

See all 45 Massachusetts spots →

Open Plainfield on the map

Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.