Adams Brook: Serpentine & Quartz Rockhounding in Windham County, Vermont
Updated July 2026
Adams Brook in the far southeast corner of Vermont tumbles varicolored serpentine boulders with red, orange, and green agate and clear quartz, a distinctive mix for the state. Tourmaline and garnet also turn up in the streambed. It is a genuine Vermont serpentine and agate locality near the Harriman Reservoir in Whitingham. Reported finds include serpentine, quartz, red agate, orange agate, green agate. Below: coordinates, access notes, nearby spots, and trip-planning links.
Adams Brook photos
Public image records connected to this spot or its reported material.
Map showing Adams Brook in Windham County, Vermont
Quick details
- Access
- Public area
- County
- Windham County
- State
- Vermont
- Nearest road
- Adams Hill Road
- Postcode
- 05351
- Coordinates
- 42.95077, -72.75817
Geology at Adams Brook
This spot sits on Meta-ultramafic rocks - undifferentiated, mapped as metadunite, metaperidotite, and serpentinite that formed roughly 1000 to 485 million years ago. Metamorphic rock like this weathers into resistant float, and minerals that survive transport typically concentrate in nearby drainages.
- Mapped unit
- Meta-ultramafic rocks - undifferentiated
- Age
- 1000–485 Ma (Neoproterozoic to Cambrian)
- Rock types
- metadunite, metaperidotite, and serpentinite
- Elevation
- 1,040 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 Adams Brook
Best months: April to November. Typical highs run 78°F in midsummer and 31°F in midwinter, with winter lows near 14°F.
Climate normals: NOAA 1991-2020 monthlies, ROWE 3NE station (16 mi away), adjusted for elevation.
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 Adams Brook
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 Adams Brook.
- BenningtonTop pick in VermontBennington County, Vermont · 19 mi awayBlue Quartz, Garnet, Feldspar
- GassettsTop pick in VermontWindsor County, Vermont · 27 mi awayQuartz, Garnet, Tourmaline
- Devil's DenTop pick in VermontRutland County, Vermont · 29 mi awaySmoky Quartz, Quartz, Pyrite
- PerkinsvilleWindsor County, Vermont · 30 mi awayPyrite, Pyrrhotite, Chlorite
- LudlowTop pick in VermontWindsor County, Vermont · 31 mi awayTourmaline, Pyrite, Talc
- Camp Plymouth State ParkTop pick in VermontWindsor County, Vermont · 36 mi awayGold
- Round HillRutland County, Vermont · 43 mi awayGreen Aventurine
- ProctorRutland County, Vermont · 49 mi awayMarble
Across the state line from Adams Brook
Adams Brook is close enough to the Vermont border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.
- Park HillCheshire County, New Hampshire · 15 mi awayStaurolite
- Spofford LakeCheshire County, New Hampshire · 16 mi awayFluorite
- HinsdaleCheshire County, New Hampshire · 19 mi awayPink Rhodonite
- Davis MineFranklin County, Massachusetts · 19 mi awayChalcopyrite, Pyrite
- Derry HillCheshire County, New Hampshire · 21 mi awayBeryl, Rose Quartz
- NorthfieldFranklin County, Massachusetts · 23 mi awayFluorite, Garnet, Golden Beryl
Adams Brook FAQ
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More rockhounding in Vermont
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