Chalcedony has been recorded at 52 places in 18 states on the USA Rockhounding map. Indiana, Illinois and North Dakota have the most. 0 are marked Ready, 6 Conditional and 45 research only, so check each place’s status before you go.
Chalcedony sites by state
| State | Sites | Ready | State guide |
|---|---|---|---|
| Indiana | 11 | 0 | Indiana rockhounding map |
| Illinois | 8 | 0 | Illinois rockhounding map |
| North Dakota | 6 | 0 | North Dakota rockhounding map |
| Nebraska | 4 | 0 | Nebraska rockhounding map |
| Texas | 4 | 0 | Texas rockhounding map |
| Washington | 3 | 0 | Washington rockhounding map |
| Mississippi | 2 | 0 | Mississippi rockhounding map |
| Missouri | 2 | 0 | Missouri rockhounding map |
| South Dakota | 2 | 0 | South Dakota rockhounding map |
| Tennessee | 2 | 0 | Tennessee rockhounding map |
| Idaho | 1 | 0 | Idaho rockhounding map |
| Iowa | 1 | 0 | Iowa rockhounding map |
| Kentucky | 1 | 0 | Kentucky rockhounding map |
| Louisiana | 1 | 0 | Louisiana rockhounding map |
| Michigan | 1 | 0 | Michigan rockhounding map |
| Minnesota | 1 | 0 | Minnesota rockhounding map |
| Rhode Island | 1 | 0 | Rhode Island rockhounding map |
| Wisconsin | 1 | 0 | Wisconsin rockhounding map |
Places to find chalcedony
Sorted with Ready sites first.
- Warsaw Formation Streams & Ravines — Geode Context, Lee / Henry / Van Buren County, Iowa: Conditional
- Mississippi Gravel Agate/Petrified-Wood Hunting — Rights-Gated Context, Statewide gravel deposits and drainages County, Mississippi: Conditional
- Nebraska Private Mine / Quarry / Ranch Field Trips, Statewide County, Nebraska: Conditional
- Mount Hope Bay Shore — Mineral/Beach-Gravel Context, Bristol / Newport County, Rhode Island: Conditional
- Buffalo Gap National Grassland — Rock / Agate / Fossil Context, Fall River / Custer / Pennington / Jackson / Oglala Lakota alias County, South Dakota: Conditional
- Red Top Trail — Agate Beds, Kittitas County, Washington: Conditional
- Knife River Flint Cultural-Sensitivity Gate, Dunn / Mercer / Oliver County, North Dakota: Rules apply
- Rabbit Springs Chalcedony and Thunder Eggs, Twin Falls County, Idaho: Research only
- Adams Rockhounding & Geology Research Index, Adams County, Illinois: Research only
- Brown Rockhounding & Geology Research Index, Brown County, Illinois: Research only
- Hamilton / Hancock County Geode Context, Hancock County, Illinois: Research only
- Hancock Rockhounding & Geology Research Index, Hancock County, Illinois: Research only
- Henderson Rockhounding & Geology Research Index, Henderson County, Illinois: Research only
- Mercer Rockhounding & Geology Research Index, Mercer County, Illinois: Research only
- Schuyler Rockhounding & Geology Research Index, Schuyler County, Illinois: Research only
- Illinois Geode Research Index, Western Illinois County, Illinois: Research only
- Brown Rockhounding & Geology Research Index, Brown County, Indiana: Research only
- South-Central Indiana Geode Belt, Brown / Monroe / Morgan / Owen / Putnam / Lawrence / Washington / Harrison County, Indiana: Research only
- Crawford Rockhounding & Geology Research Index, Crawford County, Indiana: Research only
- Harrison Rockhounding & Geology Research Index, Harrison County, Indiana: Research only
- Lawrence Rockhounding & Geology Research Index, Lawrence County, Indiana: Research only
- Monroe Rockhounding & Geology Research Index, Monroe County, Indiana: Research only
- Morgan Rockhounding & Geology Research Index, Morgan County, Indiana: Research only
- Orange Rockhounding & Geology Research Index, Orange County, Indiana: Research only
- Owen Rockhounding & Geology Research Index, Owen County, Indiana: Research only
- Putnam Rockhounding & Geology Research Index, Putnam County, Indiana: Research only
- Washington Rockhounding & Geology Research Index, Washington County, Indiana: Research only
- Kentucky Agate Research, Estill / Powell / Jackson / Rockcastle County, Kentucky: Research only
- Louisiana Agate in Gravel Research, Statewide County, Louisiana: Research only
- Lake Superior Agate Research, Keweenaw / Houghton / Ontonagon / Gogebic / Baraga / Marquette / Alger / Luce / Chippewa County, Michigan: Research only
- Lake Superior Agate Research, Cook / Lake / St. Louis / statewide glacial deposits County, Minnesota: Research only
- Mississippi Agate, Carnelian & Jasper Gravel Research, Statewide County, Mississippi: Research only
- Benton County Mozarkite Belt, Benton County, Missouri: Research only
- Clark County / St. Francisville Geode District, Clark County, Missouri: Research only
- Pine Ridge Agate / Jasper Research, Dawes / Sioux / Sheridan County, Nebraska: Research only
- Nebraska Blue Chalcedony Research, Western / central Nebraska County, Nebraska: Research only
- Nebraska Prairie Agate Research, Western Nebraska County, Nebraska: Research only
- Little Missouri River Agate / Jasper / Petrified Wood Research, Billings / McKenzie / Dunn / Slope / Golden Valley County, North Dakota: Research only
- Knife River Flint / Chalcedony Geology Research, Dunn / Mercer / Oliver County, North Dakota: Research only
- Cannonball River Gravel / Concretion Research, Morton / Grant / Sioux County, North Dakota: Research only
- North Dakota Badlands Chalcedony / Jasper Research, Western North Dakota County, North Dakota: Research only
- Missouri River Gravel & Glacial Stone Research, Williams / McKenzie / Mountrail / McLean / Mercer / Morton / Burleigh County, North Dakota: Research only
- Fairburn Agate Belt Research, Pennington / Custer / Fall River County, South Dakota: Research only
- Paint Rock Agate Research, Franklin / Marion County, Tennessee: Research only
- Tennessee Agate Research, Statewide / Highland Rim / Cumberland Plateau County, Tennessee: Research only
- Alpine / Brewster County Agate Context, Brewster County, Texas: Research only
- Woodward Ranch Agate Historic Locality, Brewster County, Texas: Research only
- Canadian River Gravel / Agate Context, Potter / Hutchinson / Roberts County, Texas: Research only
- Marfa / Presidio County Agate Context, Presidio County, Texas: Research only
- Okanogan-Wenatchee National Forest — Personal Use Rockhounding Policy, MULTI County, Washington: Research only
- Walker Valley — Geode Collecting Context, Skagit County, Washington: Research only
- Lake Superior Agate Research, Bayfield / Ashland / Douglas / Iron County, Wisconsin: Research only
What chalcedony is
Chalcedony is a form of quartz made of fibres too small to see, which gives it a smooth, waxy look. Agate is banded chalcedony, carnelian is orange-red chalcedony, and chrysoprase is apple-green. Plain chalcedony is often white, grey or pale blue, and it commonly forms botryoidal (grape-like) crusts, nodules and “desert roses”.
How to identify chalcedony
- Translucent with a waxy lustre.
- Hard enough to scratch glass.
- Smooth, rounded or bubbly surfaces; conchoidal fracture.
- No visible crystals, unlike crystalline quartz.
Where chalcedony is found
It is common in volcanic regions of the West, including Oregon, Nevada, Arizona, California, Idaho and Utah, and in gravels and beaches carrying agate, such as the Lake Superior shores and the Yellowstone River. Blue chalcedony from the Holley area of Oregon and Ellensburg Blue agate from Washington are prized.
Rules
Hobby collecting is allowed in reasonable amounts on most BLM land and in many national forests. Many prized deposits are on private claims or ranches; ask first.
Questions
What is the difference between chalcedony and agate?
Agate is a banded variety of chalcedony. Both are microcrystalline quartz; chalcedony without bands or patterns is simply called chalcedony.
Where can I find chalcedony?
In volcanic areas of Oregon, Nevada, Arizona, California and Idaho, and in agate-bearing gravels such as the Lake Superior shores and the Yellowstone River.
What the map statuses mean is explained in how map statuses work; collecting rules for each kind of land are in rules by land type.
Other rocks and minerals
Agate · Geodes · Quartz · Jasper · Petrified Wood · Fossils · Shark Teeth · Gold · Garnet · Sapphire · Crystals · Calcite · Copper · Diamonds · Fluorite · Mica · Pyrite · Beryl, Aquamarine & Emerald · Tourmaline
Data: USA Rockhounding atlas records, checked through 2026-08-30. See all rocks and minerals.