Best spot

Gem Hill: Agate & Chalcedony Rockhounding in Kern County, California

Updated June 2026

Gem Hill is a focused Kern County silica locality, with Mindat recording agate, chalcedony, iris agate, jasper, petrified wood, native gold, and uranium minerals nearby. Its appeal is the Rosamond Hills mix of lapidary material and desert mineralization, but claim and parcel checks matter because the district has a long mining history. Reported finds include agate, chalcedony, jasper, uraninite, obsidian. Below: coordinates, access notes, nearby spots, and trip-planning links.

Gem Hill photos

Public image records connected to this spot or its reported material.

1 photo

Botryoidal blue chalcedony from the Mojave Desert, California at Gem Hill, Kern County, California

Quick details

Access: Public area
County: Kern County
State: California
Coordinates: 34.92490, -118.22182

Geology at Gem Hill

This spot sits on pyroclastic and volcanic mudflow deposits, unit 8 (Northern Mojave Desert), mapped as rhyolite that formed roughly 23 to 4 million years ago. Volcanic ground like this is where agate, jasper, and other chalcedony typically form, filling old gas pockets and fracture seams in the flow rock.

Mapped unit: pyroclastic and volcanic mudflow deposits, unit 8 (Northern Mojave Desert)
Age: 23–4 Ma (Early Miocene to Early Pliocene)
Rock types: rhyolite
Elevation: 2,960 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 Gem Hill

Best months: September to June. Typical highs run 96°F in midsummer and 57°F in midwinter, with winter lows near 32°F. Summer heat here is intense, so carry more water than you think you need and work the early morning.

Climate normals: NOAA 1991-2020 monthlies, MOJAVE station (9 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.

State guidance last verified: April 1, 2026

BLM California — Recreational mineral collecting
California Geological Survey
CDFW — Suction Dredge Mining Permit Program
Community submissions reviewed against published agency rules

Found at Gem Hill

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 Gem Hill.

Gem Hill FAQ

Where is Gem Hill?+

Gem Hill is in Kern County, California, at 34.92490, -118.22182.

What rocks and minerals can you find at Gem Hill?+

Gem Hill is reported to produce Agate, Chalcedony, Jasper, Uraninite, Obsidian.

Is collecting allowed at Gem Hill?+

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 Gem Hill?+

Most agate and jasper is surface float: bring a spray bottle, a pick or small shovel, and a sturdy bag. Wet stones show their banding and translucence.

When is the best time to visit Gem Hill?+

The most comfortable months at Gem Hill are September to June. Summer heat here is intense, so carry more water than you think you need and work the early morning.

How do I get to Gem Hill?+

Open the directions link to navigate to 34.92490, -118.22182 in Google Maps. Some spots are remote, so check road conditions before driving out.

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