Indianapolis: Moonstone Rockhounding in Marion County, Indiana

Updated June 2026

Indianapolis is a mapped rockhounding spot in Marion County, Indiana. Reported finds include moonstone. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Marion County
State: Indiana
Nearest road: South Harding Street
Postcode: 46217
Coordinates: 39.70946, -86.20313

Geology at Indianapolis

This spot sits on ground mapped as Rockford Limestone and New Albany Shale that formed roughly 420 to 325 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: Rockford Limestone and New Albany Shale
Age: 420–325 Ma (Devonian to Mississippian)
Elevation: 680 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 Indianapolis

Best months: March to November. Typical highs run 86°F in midsummer and 37°F in midwinter, with winter lows near 22°F.

Climate normals: NOAA 1991-2020 monthlies, INDIANAPOLIS station (4 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 Indianapolis

Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Moonstone Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of Indianapolis.

Across the state line from Indianapolis

Indianapolis is close enough to the Indiana border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Hueston Woods State ParkTop pick in OhioPreble County, Ohio · 78 mi awayFossils, Trilobites, Brachiopods

Indianapolis FAQ

Where is Indianapolis?+

Indianapolis is in Marion County, Indiana, at 39.70946, -86.20313. Nearest road: South Harding Street.

What rocks and minerals can you find at Indianapolis?+

Indianapolis is reported to produce Moonstone.

Is collecting allowed at Indianapolis?+

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 Indianapolis?+

A rock hammer, sturdy gloves, safety glasses, and a collecting bag cover the basics here. Add a spray bottle: wet rock shows color and pattern that dry rock hides.

When is the best time to visit Indianapolis?+

The most comfortable months at Indianapolis are March to November.

How do I get to Indianapolis?+

Open the directions link to navigate to 39.70946, -86.20313 in Google Maps. The nearest road is South Harding Street.

More rockhounding in Indiana

See all 33 Indiana spots →

Open Indianapolis on the map

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