Cinque Quarry: Amethyst & Smoky Quartz Rockhounding in South Central Connecticut Planning Region, Connecticut

Updated June 2026

Cinque Quarry is a mapped rockhounding spot in South Central Connecticut Planning Region, Connecticut. Reported finds include amethyst, smoky quartz. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: South Central Connecticut Planning Region
State: Connecticut
Nearest road: McLay Avenue
Postcode: 06512
Coordinates: 41.30111, -72.86528

Geology at Cinque Quarry

This spot sits on Buttress Dolerite, mapped as basalt and gabbro that formed roughly 175 to 160 million years ago. Cavities and seams in volcanic rock like this are the kind of setting where quartz and amethyst crystals tend to grow.

Mapped unit: Buttress Dolerite
Age: 175–160 Ma (Middle Jurassic)
Rock types: basalt and gabbro
Elevation: 140 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 Cinque Quarry

Best months: March to November. Typical highs run 82°F in midsummer and 38°F in midwinter, with winter lows near 23°F.

Climate normals: NOAA 1991-2020 monthlies, NEW HAVEN TWEED AP station (3 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 Cinque Quarry

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 Cinque Quarry.

Across the state line from Cinque Quarry

Cinque Quarry 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.

Cinque Quarry FAQ

Where is Cinque Quarry?+

Cinque Quarry is in South Central Connecticut Planning Region, Connecticut, at 41.30111, -72.86528. Nearest road: McLay Avenue.

What rocks and minerals can you find at Cinque Quarry?+

Cinque Quarry is reported to produce Amethyst, Smoky Quartz.

Is collecting allowed at Cinque Quarry?+

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 Cinque Quarry?+

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 Cinque Quarry?+

The most comfortable months at Cinque Quarry are March to November.

How do I get to Cinque Quarry?+

Open the directions link to navigate to 41.30111, -72.86528 in Google Maps. The nearest road is McLay Avenue.

More rockhounding in Connecticut

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Open Cinque Quarry on the map

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