Where to Find Chalcedony in Colorado

Colorado has 5 mapped collecting spots that report chalcedony, spread across 3 counties. The largest share sits in Mineral County with 3 spots. 3 of the spots are on land mapped as publicly accessible, and 1 is a fee-dig site.

Standout chalcedony spots in Colorado

Hand-picked from the full list below, with the reason each one earns a trip.

Del Norte Thunder Egg Beds
Saguache County
The thunderegg beds northwest of Del Norte have yielded plume and moss agate from rhyolite flows since the late 1800s, with chalcedony, common opal, and quartz-lined cavities documented at the locality.

Best counties for chalcedony in Colorado

Ranked by the number of mapped chalcedony spots. County links open the full rockhounding page for that county.

Every chalcedony spot we track in Colorado

Sorted by county. Coordinates open in Google Maps.

Spot	County	Minerals	Coordinates	Access
Austin BluffsWittenberg Court	El Paso County	Agate Carnelian Chalcedony Jasper	38.9072, -104.7973	Public
Last Chance MineBachelor Road	Mineral County	Amethyst Agate Chalcedony Quartz Silver Acanthite Galena Sphalerite +2 more	37.8839, -106.9367	Paid / fee
Willow Creek (permission required)West Willow Creek Road	Mineral County	Amethyst Chalcedony Sphalerite Silver Agate	37.8700, -106.9292	Permission
Wolf Creek Stream BedUS 160	Mineral County	Amethyst Geode Agate Chalcedony Jasper Moonstone	37.4873, -106.8203	Public
Del Norte Thunder Egg Beds	Saguache County	Plume Agate Moss Agate Chalcedony Common Opal Quartz	37.7615, -106.4481	Public

Before you go

Read the chalcedony identification guide so you know what a keeper looks like in the field: Chalcedony in the encyclopedia.

Chalcedony in Colorado FAQ

Where can you find chalcedony in Colorado?+

The mapped spots concentrate in Mineral County, El Paso County, and Saguache County. Every spot on this page appears on the map above with coordinates and access notes.

How many chalcedony spots are mapped in Colorado?+

5 spots across 3 counties. The RockHoundR app keeps the same spots on an offline map with public land overlays, geology layers, and your saved finds.

Is it legal to collect chalcedony in Colorado?+

Hand collecting of common rocks and minerals in small amounts for personal use is generally allowed on BLM and U.S. Forest Service land, with limits set by the local field office. National parks, most state parks, and tribal land are closed to collecting. 3 of the 5 mapped spots here sit on land marked public, and 1 is a fee-dig operation where you pay for access and keep what you find. Always confirm current rules with the managing agency before you dig.

Where else to find chalcedony

More minerals to hunt in Colorado

Hunt chalcedony in Colorado with the map in your pocket

RockHoundR puts these spots on an offline map with BLM and Forest Service overlays, geology layers, and a log for your finds.