Plum Bank Beach: Agate & Moonstone Rockhounding in Lower Connecticut River Valley Planning Region, Connecticut
Updated July 2026
Plum Bank Beach is one of Connecticut's more reliable shoreline spots for surface agate and moonstone, tumbled from glacial outwash and concentrated in the beach gravel by Long Island Sound tides. The Laurentide ice sheet left the material as lag deposits, so the best picking follows low tide and storms rather than any bedrock exposure. It is casual beachcombing, not digging: finds run from pea to walnut sized chalcedony and adularescent feldspar. Reported finds include agate, moonstone. Below: coordinates, access notes, nearby spots, and trip-planning links.
Plum Bank Beach photos
Public image records connected to this spot or its reported material.
Map showing Plum Bank Beach in Lower Connecticut River Valley Planning Region, Connecticut
Quick details
- Access
- Public area
- State
- Connecticut
- Nearest road
- Plum Bank Road
- Postcode
- 06475
- Coordinates
- 41.26477, -72.39004
Geology at Plum Bank Beach
This spot sits on ground mapped as Unknown - Unmapped. Tough silica like agate and jasper typically survives weathering and collects as float in drainages and gravel.
- Mapped unit
- Unknown - Unmapped
- Elevation
- 10 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 Plum Bank Beach
Best months: March to December. Typical highs run 82°F in midsummer and 39°F in midwinter, with winter lows near 25°F.
Climate normals: NOAA 1991-2020 monthlies, ORIENT PT SP station (11 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 Plum Bank Beach
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 Plum Bank Beach.
- CCC QuarryTop pick in ConnecticutLower Connecticut River Valley Planning Region, Connecticut · 15 mi awayBeryl, Aquamarine, Microcline
- Gillette QuarryLower Connecticut River Valley Planning Region, Connecticut · 17 mi awayAmazonite, Aquamarine, Beryl
- Guilford & East HavenTop pick in ConnecticutSouth Central Connecticut Planning Region, Connecticut · 19 mi awayAgate
- Slocum ProspectLower Connecticut River Valley Planning Region, Connecticut · 19 mi awayBeryl, Rose Quartz
- New LondonSoutheastern Connecticut Planning Region, Connecticut · 21 mi awayApatite, Spodumene
- New Haven Traprock QuarrySouth Central Connecticut Planning Region, Connecticut · 22 mi awayAmethyst
- StaffordSoutheastern Connecticut Planning Region, Connecticut · 22 mi awayIron Ore, Limonite, Quartz
- White Rocks QuarryLower Connecticut River Valley Planning Region, Connecticut · 23 mi awayBeryl, Tourmaline
Across the state line from Plum Bank Beach
Plum Bank Beach is close enough to the Connecticut border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.
- WesterlyTop pick in Rhode IslandSouth County, Rhode Island · 35 mi awayBeryl
- Long Island South Shore BeachesTop pick in New YorkSuffolk County, New York · 44 mi awayAlmandine Garnet, Quartz, Jasper
- Moosup RiverProvidence County, Rhode Island · 47 mi awayEpidote, Hornblende, Orthoclase
- West GreenwichKent County, Rhode Island · 48 mi awayAmazonite
- NarragansettTop pick in Rhode IslandSouth County, Rhode Island · 52 mi awayBeryl, Quartz
- Jamestown BridgeTop pick in Rhode IslandNewport County, Rhode Island · 55 mi awayStaurolite
Plum Bank Beach FAQ
Where is Plum Bank Beach?+
What rocks and minerals can you find at Plum Bank Beach?+
Is collecting allowed at Plum Bank Beach?+
What tools should I bring to Plum Bank Beach?+
When is the best time to visit Plum Bank Beach?+
How do I get to Plum Bank Beach?+
More rockhounding in Connecticut
See all 51 Connecticut spots →Open Plum Bank Beach on the map
Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.
