Where to Find Chalcedony in Texas

Texas chalcedony tracks the same Trans-Pecos volcanic belt that produces the state's agate. Brewster and Presidio counties yield red, pink, and white chalcedony in the Tascotal and Mitchell Mesa tuffs, often as nodule rinds on plume agate. Marfa-area chalcedony runs softer and pinker; Big Bend chalcedony is harder and more saturated. Smaller showings of milky and gray chalcedony turn up in the Llano uplift of central Texas. Most ground is on private ranches that run dig days; trespass on Texas ranchland is prosecuted aggressively. Coastal Texas adds occasional chalcedony beach pebbles along the Padre Island shoreline.

Spot list checked against source data on April 1, 2026.

Best counties for chalcedony in Texas

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

Brewster County3 spots
Hudspeth County1 spot
Jeff Davis County1 spot
Live Oak County1 spot
Maverick County1 spot
Presidio County1 spot
San Saba County1 spot
Starr County1 spot
Trinity County1 spot
Webb County1 spot
Zapata County1 spot

Every chalcedony spot we track in Texas

Sorted by county. Coordinates open in Google Maps.

Spot	County	Minerals	Coordinates	Access
General AreaCalamity Creek Road	Brewster County	Moss Agate Plume Agate Chalcedony Jasper Quartz	30.1676, -103.5948	Public
Terlingua CreekJoe Moss Road	Brewster County	Amber Agate Chalcedony Jasper	29.2906, -103.5475	Public
W side of Glass Mountains	Brewster County	Moss Agate Plume Agate Chalcedony Jasper Quartz	30.3704, -103.4002	Public
Quitman Mountains (South)	Hudspeth County	Agate Amethyst Carnelian Chalcedony Jasper Petrified Wood	31.1005, -105.5080	Public
Marfa and Ft. DavisTX 17	Jeff Davis County	Agate Chalcedony Jasper	30.4511, -103.9821	Public
H.D. House Ranch areaTX 72	Live Oak County	Agatized Fern Buds Jasper Chalcedony	28.4665, -98.2258	Public
Eagle PassStone Hill	Maverick County	Agate Amber Chalcedony Jasper	28.7373, -100.4712	Public
Chinati Mts	Presidio County	Agate Chalcedony Jasper	30.0004, -104.3529	Public
Hinton CreekCo 364	San Saba County	Chalcedony Chert	31.0145, -99.0645	Public
Rio Grande	Starr County	Agate Chalcedony Jasper	26.3624, -98.8352	Public
Btwn Groveton & Trinity	Trinity County	Agate Chalcedony Jasper Petrified Wood	31.0331, -95.2220	Public
Rio Grande River AreaRio Grande Vega Trail	Webb County	Agate Agatized Wood Chalcedony Jasper	27.4979, -99.4922	Public
LopenoEl Tigre Road	Zapata County	Agate Agatized Wood Chalcedony Jasper	26.7131, -99.1313	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 Texas FAQ

Where can you find chalcedony in Texas?+

The mapped spots concentrate in Brewster County County, Hudspeth County County, and Jeff Davis County County. Known collecting areas include Woodward Ranch (Brewster County), Marfa volcanics (Presidio County), and Llano uplift (Mason County). Every spot on this page appears on the map above with coordinates and access notes.

How many chalcedony spots are mapped in Texas?+

13 spots across 11 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 Texas?+

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. 13 of the 13 mapped spots here sit on land marked public. Always confirm current rules with the managing agency before you dig.

Where else to find chalcedony

More minerals to hunt in Texas

Hunt chalcedony in Texas 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.