Grand Isle: Quartz & Calcite Rockhounding in Grand Isle County, Vermont

Updated June 2026

Grand Isle is a mapped rockhounding spot in Grand Isle County, Vermont. Reported finds include quartz, calcite, pyrite concretions. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Grand Isle County
State: Vermont
Nearest road: Nautical Court
Postcode: 05486
Coordinates: 44.63220, -73.27040

Geology at Grand Isle

This spot sits on Stony Point Formation, mapped as shale and limestone that formed roughly 460 to 445 million years ago. Carbonate rock like this dissolves and weathers readily, so fresh road cuts, quarries, and creek exposures are typically the most productive ground.

Mapped unit: Stony Point Formation
Age: 460–445 Ma (Late Ordovician)
Rock types: shale and limestone
Elevation: 120 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 Grand Isle

Best months: April to November. Typical highs run 81°F in midsummer and 28°F in midwinter, with winter lows near 11°F.

Climate normals: NOAA 1991-2020 monthlies, S HERO station (2 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 Grand Isle

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 Grand Isle.

Across the state line from Grand Isle

Grand Isle 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.

Grand Isle FAQ

Where is Grand Isle?+

Grand Isle is in Grand Isle County, Vermont, at 44.63220, -73.27040. Nearest road: Nautical Court.

What rocks and minerals can you find at Grand Isle?+

Grand Isle is reported to produce Quartz, Calcite, Pyrite Concretions.

Is collecting allowed at Grand Isle?+

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 Grand Isle?+

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 Grand Isle?+

The most comfortable months at Grand Isle are April to November.

How do I get to Grand Isle?+

Open the directions link to navigate to 44.63220, -73.27040 in Google Maps. The nearest road is Nautical Court.

More rockhounding in Vermont

See all 29 Vermont spots →

Open Grand Isle on the map

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