Updated July 2026
17 mapped spots for rock hunting and rock collecting across 5 counties. Rhode Island rockhounding is beach stones and Blackstone Valley bedrock: jasper, agate, carnelian, and quartz pebbles on the Narragansett Bay and South County shores, the great quartz outcrop of Diamond Hill in Cumberland with its historic amethyst, bowenite serpentine from the Lincoln and Cumberland marble belt, and the state rock, cumberlandite, from Iron Mine Hill.
The best rockhounding in Rhode Island is at Bristol in Bristol County (jasper), Warwick in Kent County (carnelian), and Johnston in Providence County (amethyst). In total, 17 mapped collecting spots across 5 counties produce quartz, jasper, and amethyst, each listed below with its land access.
Best spotMt. Hope BayBristol County, Rhode IslandPublic access · Red Agate, Amethyst, Carnelian +3
Best spotPawtuxetProvidence County, Rhode IslandPublic access · Agate, Carnelian, Amethyst +1
Best spotDiamond Hill Park, CumberlandProvidence County, Rhode IslandPublic access · Amethyst, Quartz, Smoky Quartz
Best spotNorth ProvidenceProvidence County, Rhode IslandPublic access · Bowenite, Quartz, Serpentine
Best spotNarragansettSouth County, Rhode IslandPublic access · Beryl, Quartz
Best spotBristolBristol County, Rhode IslandPublic access · Jasper
Best spotJamestown BridgeNewport County, Rhode IslandPublic access · Staurolite
Best spotJohnstonProvidence County, Rhode IslandPublic access · Amethyst
Best spotWarwickKent County, Rhode IslandPublic access · Carnelian
Best spotWesterlySouth County, Rhode IslandPublic access · Beryl
Moosup RiverProvidence County, Rhode IslandPublic access · Epidote, Hornblende, Orthoclase +7Sneech PondProvidence County, Rhode IslandPublic access · Chalcopyrite, Garnet, Magnetite +2Cumberland HillProvidence County, Rhode IslandPublic access · Agate, Chalcedony, Jasper +1ProvidenceProvidence County, Rhode IslandPublic access · Agate, Chalcedony, Jasper +1JohnstonProvidence County, Rhode IslandPublic access · QuartzTivertonNewport County, Rhode IslandPublic access · QuartzWest GreenwichKent County, Rhode IslandPublic access · AmazoniteRepresentative spot and material photos from locations in this state, shown where verified public image records are available.
Counts reflect how many spots in this list mention each mineral.
Notable areas: Diamond Hill quartz, Lincoln bowenite, Iron Mine Hill cumberlandite, and South County beach carnelian and jasper are the Rhode Island targets collectors travel for.
Rhode Island is Avalonian basement: Precambrian and Cambrian granite, gneiss, and marble in the northeast around Lincoln and Cumberland, the Pennsylvanian Narragansett Basin of sandstone, shale, and coal under Providence and the bay, and Devonian granites in the west and south. The Blackstone Valley marble and serpentinite around Lime Rock and Lincoln produced bowenite, the apple-green serpentine that is the state mineral, and Iron Mine Hill in Cumberland is the only outcrop of cumberlandite, a magnetite-rich rock that is the state rock. Diamond Hill in Cumberland is a massive quartz vein, once a source of amethyst and clear quartz, now a town park. Small pegmatites around Johnston and North Providence carried beryl and amazonite. Glacial drift and the ocean built the beaches of Narragansett, Westerly, Warwick, Bristol, and Jamestown, which concentrate jasper, agate, carnelian, and quartz pebbles from bedrock to the north.
Diamond Hill Park's quartz, bowenite in the Lime Rock marble belt, cumberlandite at Iron Mine Hill, and pegmatite minerals around Johnston. Town park rules and private land govern access.
Jasper, agate, and quartz pebbles at Mt. Hope Bay, Warwick's bay beaches, Pawtuxet, and the Jamestown Bridge shore, surface picking on public beaches.
Carnelian, jasper, and agate pebbles on the ocean beaches after winter storms and on falling tides. Town beaches allow picking; state beaches do not allow removal.
November through March for the beaches, after storms and at low tide, before summer beach rules and crowds; winter also empties the shore of parking fees. Inland sites are best in April and May and in October after leaf-off.
A spray bottle, a mesh bag, and a tide table for the beaches; a rock hammer, safety glasses, and a hand lens for the Blackstone Valley, though most sites are look-and-pick rather than hammer-and-chisel. Warm layers for winter shore days.
Diamond Hill's quartz has been noted since colonial times and its amethyst was collected in the 1800s. The Lime Rock quarries supplied lime and marble from the 1600s. Bowenite became the state mineral and cumberlandite the state rock in 1966.
Day-trip range. Each section lists the closest mapped rockhounding spots within about 150 miles of the city. Most are inside a 2 to 3 hour drive.
6 closest spots to Providence, RI.
Geology rarely respects state borders. These states share mapped rockhounding country with Rhode Island, useful when Rhode Island is the start, not the whole trip. Each card links to the closest county across the line.
County pages are linked once we have at least 3 mapped spots for a focused guide with coordinates, mineral notes, and nearby spots.
Hand-picked standouts from the Rhode Island list, chosen for unusual mineralogy, documented public access, or both. Each card links to coordinates, access notes, and what to look for.
Top pickBristol County
The Bristol shoreline, including the public waterfront at Colt State Park and the town beaches, yields red and brown jasper pebbles along with occasional agate and quartz from the Narragansett Basin conglomerates.
Jasper
Top pickKent County
Warwick's Narragansett Bay beaches, including the public shore around Conimicut Point and City Park, are a long-known source of water-worn carnelian and agate pebbles.
Carnelian
Top pickProvidence County
The rock cuts and volcanic outcrops in Johnston, near the Route 6 and Interstate 295 corridor, have produced amethyst and clear to smoky quartz from vugs in the underlying felsic bedrock.
Amethyst
Top pickNewport County
The metamorphic rocks near the Jamestown bridge landing on Conanicut Island carry staurolite, the cross-shaped iron-aluminum silicate prized by collectors, along with serpentine tied to the same belt that produces the state's bowenite.
Staurolite
Top pickBristol County
The beach gravels rimming Mt. Hope Bay hold Rhode Island's fullest spread of chalcedony, including red and green agate, carnelian, jasper, and thin plates of hematite eroded from the Narragansett Basin.
Red Agate, Amethyst, Carnelian, Jasper
Top pickProvidence County
The Narragansett Bay beach gravels at Pawtuxet Village turn up agate, carnelian, amethyst, and jasper pebbles, the same chalcedony suite that washes out of the region's volcanic and glacial deposits.
Agate, Carnelian, Amethyst, Jasper
Top pickProvidence County
The serpentine belt running through northern Rhode Island is the home of bowenite, the state mineral, a hard translucent green serpentine close enough to jade to be cut as a gemstone.
Bowenite, Quartz, Serpentine
Top pickSouth County
The pegmatite outcrops along the Bonnet Shores coast in Narragansett carry beryl and quartz in coarse granitic pods, a rare chance to see gem-family minerals in place on a public Rhode Island shore.
Beryl, Quartz
Top pickSouth County
Westerly is famous for its fine-grained granite, and the pegmatite dikes cutting that granite have yielded smoky quartz crystals up to six inches and occasional beryl.
Beryl
Top pickProvidence County
Diamond Hill is a massive white quartz outcrop with a 350-foot vertical face, historically Rhode Island's most famous locality for milky and smoky quartz and the amethyst that gave the hill its name.
Amethyst, Quartz, Smoky Quartz
1 club in Rhode Island. Clubs run field trips, shows and workshops, and many trips go to private claims you can't reach alone.
Open the RockHoundR app to see Rhode Island on a real map with public land overlays, weather, geology, and your saved finds.
