Most agates people find or inherit are worth about $1-20 each as of late 2026. Tumbler-grade rough agate, including Lake Superior agate from Minnesota and Michigan, sells for roughly $15-20 a pound from rock shops, and dyed Brazilian agate slices, the bright blue, pink and purple ones sold as coasters and suncatchers, sell for a few dollars each. The money is in quality: a sharply banded Lake Superior agate of an inch or two with good color brings about $50-200, a large, whole, finely banded "laker" can bring several hundred dollars, and the rare exceptional big ones more. Fire agate cut into a cabochon with bright, even iridescence sells for roughly $20-300, more for rare top stones.
Three things decide the value of an agate: the pattern (how fine, sharp and complete the banding is), the color, and the size and wholeness of the stone. The location adds a premium on top, because collectors pay for a Lake Superior, Laguna, Fairburn or Montana agate in a way they do not for an anonymous tumbled stone.
Quick answer
- Common agate, tumbled stones and dyed slices: about $1-15 each. Tumbler rough: roughly $15-20 a pound.
- Lake Superior agate: $2-20 for small ordinary pieces, roughly $50-200 for fine banded stones of 1 to 2 inches, several hundred for large fine ones, and more only for rare exceptional stones.
- Fire agate cabochons: roughly $20-300, priced on brightness and color; top stones higher.
- Dyed agate is common and inexpensive. Unnatural blue, pink, purple and bright green almost always mean dye.
How to identify and value an agate, step by step
- Check that it is chalcedony. Agate is banded chalcedony, a form of quartz. It scratches glass, has a waxy to glassy shine on a broken surface and breaks with smooth, curved, shell-like (conchoidal) fractures. A stone that a steel knife scratches easily is not agate.
- Do the flashlight test. Press a bright flashlight against the stone in a dark room. Agate glows through, at least at the edges, because chalcedony is translucent. Jasper, which looks similar, stays dark. Opaque, grainy stones are something else.
- Look for banding. Concentric bands following the outline of the stone, like rings in a cut onion, are the classic agate pattern. Flat, parallel "water-level" bands, eyes (small circles on the surface), moss and plume inclusions are agate too. A stone that glows but has no pattern is plain chalcedony or carnelian.
- Read the outside. A rough agate usually has a pitted, rough skin with small dimples. On Lake Superior agates, look for a waxy shine through that skin, rusty red, orange and yellow colors from iron, and bands that show on any broken face. Most lakers are found in glacial gravel in Minnesota, Wisconsin and Michigan, along the lake shore and in gravel pits.
- Check for dye. Natural agate comes in white, gray, blue-gray, tan, brown, red, orange and yellow. Bright royal blue, hot pink, purple, vivid green and jet black are almost always dyed, usually on Brazilian agate. Dye collects in the more porous bands and in cracks, so look for color that is stronger along fractures and edges.
- Look for fire. Fire agate is a brown chalcedony with thin layers of iron oxide that show rainbow iridescence when polished. Found in Arizona, California and Mexico, it is almost always cut along the bubbly (botryoidal) surface, so the colors sit in rounded bumps. Shine a light and tilt: the colors should flash and change.
- Judge pattern, color and size. Fine, tight, sharp bands that go all the way around, strong contrasting colors and a stone without fractures is high grade. Weak, fuzzy, or partial banding, internal cracks and a chunk of plain quartz in the middle all bring it down. Size matters a lot on lakers: a fine 2 inch stone is worth many times a fine 1 inch one.
- Decide rough or polished. A natural unpolished laker with its skin is often valued higher by Lake Superior collectors than a tumbled one, because tumbling removes the natural surface. For most other agate, a cut and polished face shows the pattern and helps the sale.
What agate sells for
Prices are typical sold and retail figures for natural stones as of late 2026, from rock shops, dealers and sold marketplace listings. Asking prices online often run far above what sells, especially for Lake Superior agate.
| Agate | Form and size | Typical price, as of late 2026 |
|---|---|---|
| Dyed Brazilian agate slices | Coaster or small slice | About $3-15 |
| Tumbled agate, mixed | Under 1 inch | About $0.50-2 each; $15-25 per pound |
| Lake Superior agate, tumbler rough | Bulk, 1 inch and under | Roughly $15-20 per pound |
| Lake Superior agate, ordinary banded | Under 1 inch | About $2-20 |
| Lake Superior agate, fine banded, good color | 1 to 2 inches | About $50-200 |
| Lake Superior agate, large and fine | Over 2 inches | Several hundred dollars; exceptional stones more, sales are thin |
| Botswana, Brazilian and Mexican crazy lace, polished | Hand-sized | About $10-60 |
| Laguna and Coyamito agate (Mexico), polished, fine | 2 to 3 inches | About $50-500; top pieces more |
| Montana moss agate, slab or cabochon | Slab or small cab | About $5-40 |
| Fairburn agate (South Dakota), fine | 1 to 2 inches | Hundreds of dollars; sales are thin |
| Fire agate, cabochon, faint or patchy color | 5 to 15 carats | About $10-50 |
| Fire agate, cabochon, bright even color | 5 to 20 carats | About $50-300; top stones higher |
| Agate geodes and thundereggs | Halves | See our geode value guide |
The honest picture is that nearly every agate is common. Agate is one of the most abundant collectible stones on earth and Brazil, Uruguay, Mexico, Botswana and the US produce it by the ton. Lake Superior agates are scarcer and more loved, but they are also the stone that most rockhounds in the upper Midwest pick up, and the ordinary ones sit in jars by the thousand. A Duluth dealer quoted by the Duluth News Tribune put it plainly: the big, colorful, well-banded lakers are very valuable, while the market for middle-of-the-road stones has largely gone away.
A worked example
Say you pick up a reddish, pitted stone about 1.5 inches across on a Minnesota beach. Held against a flashlight, the edge glows orange. One broken face shows tight concentric bands of red and white that run most of the way around the stone, and a small crack crosses one side. It scratches glass. That is a Lake Superior agate: the glow says chalcedony, the bands say agate and the iron colors and location say laker. The partial banding and the crack keep it from the top. A fair value is roughly $20-60. Had the bands gone all the way around with no crack, and the stone been 2.5 inches, it would be a several hundred dollar agate, and worth showing to a Lake Superior agate dealer.
What moves the price
| Factor | Effect on price |
|---|---|
| Fine, sharp, complete banding | The basis of the top of every range |
| Strong natural color (red, orange, contrasting white) | Adds 50-200 percent over pale stones |
| Size, for the same pattern | Rises steeply; a fine 2 inch laker is worth several times a fine 1 inch one |
| Internal fractures | Deduction of 30-70 percent |
| Plain quartz center taking up most of the stone | Deduction of 30-60 percent |
| Natural surface left on a laker (not tumbled) | Many collectors prefer it |
| Known locality (Lake Superior, Laguna, Fairburn, Condor) | Adds a premium over unnamed agate |
| Dyed color | Low value; sold as decor |
| Fire agate, bright even colors across the face | Several times a patchy stone |
| Cut that leaves a window through to the fire layer | Adds value; overcut stones lose color |
Fakes and treatments
Dye is by far the most common treatment. Most Brazilian agate is pale gray when mined, and a large share is dyed for the decor trade, a practice that goes back over a century. It is not deceptive when sold as decor, but a bright blue agate is not a rare natural blue. Some sellers heat agate to deepen reds and oranges, which is hard to detect and not much discussed. Glass imitations exist, especially of fire agate and of tumbled "agate" in gift shops; glass feels warmer, often has round bubbles under magnification and shows no banding structure. With Lake Superior agate, the main trick is passing off agates from elsewhere, or tumbled Brazilian stones, as lakers. Real lakers have iron colors and a pitted skin, and the people who know them well can usually tell at a glance.
On collecting: picking up agates on public beaches along Lake Superior in Minnesota is a common hobby, while state parks and national lakeshores have their own rules, and some forbid taking stones. Bureau of Land Management land in the West generally allows collecting reasonable amounts of agate for personal use, but not for sale or barter. Ask before you collect on private land.
How WorthPic reads agate photos
WorthPic runs on the newest and most capable AI model available, tuned for exactly this kind of identification. From a photo of the stone, ideally both the outside and a broken or polished face, it reads the banding pattern, the color, the translucency where light shows through and the surface texture, and suggests whether the stone is agate, jasper, chalcedony or something else, and where it may have come from. It looks for the signs of dye, such as unnatural color or color concentrated in cracks, and for the iridescence of fire agate. It then gives an honest value range for what the photos show. What a photo cannot settle is hardness, weight, whether a stone has been heated, or the fine details a collector checks with a loupe. It identifies and estimates. It does not authenticate, grade or appraise. For a large or very fine stone, a specialist agate dealer or a local rock and mineral club is the right next step.
Common mistakes
- Assuming that bright color means value. Bright blue and pink agate is dyed and inexpensive.
- Tumbling a fine laker. Tumbling removes the natural skin some collectors prefer and can take away size.
- Breaking an agate open to see inside without knowing where it will fracture. Many good lakers are ruined this way.
- Pricing from asking listings. Lake Superior agates are offered online at prices few buyers pay.
- Calling jasper an agate. If light does not pass through at the edges, it is probably jasper.
- Oiling a stone to make it look polished for photos. Buyers notice and discount.
- Taking agates from parks or lakeshores where collecting is not allowed.
What to photograph
- The whole stone in daylight, with a coin or ruler for scale.
- Any broken or polished face that shows banding, as sharp as your phone can focus.
- The stone held against a flashlight in a dark room, to show translucency.
- The rough outside skin up close.
- For fire agate, two or three angles under a single light so the play of color shows.
- For a slice or slab, both faces, held up to window light.
When to get it looked at in person
A jar of tumbled stones or a dyed slice does not need an expert; it is decor and worth what it costs in a gift shop. A local rock and mineral club, or a rock shop near where you found the stone, is the best first stop for a rough stone you cannot name; most will give an opinion in a minute. For a Lake Superior agate over 2 inches with fine banding, or a fire agate that shows strong color across the whole face, talk to a specialist agate dealer before selling, and compare sold results rather than asking prices. If the stone turns out not to be an agate, our guide on how to identify valuable rocks walks through the home tests, and agate that replaced wood is covered in petrified wood value. For other finds from the same beach or field, see identifying a found object.