Most geodes are worth about $2-30 as of late 2026. Unopened "break your own" geodes from Morocco, Mexico and the Keokuk region of Iowa, Illinois and Missouri sell for roughly $2-5 each in bulk, and boxes of 25 to 30 unopened 2 to 3 inch Keokuk geodes work out to a few dollars a geode. Opened, matched pairs of the same size with clean quartz or calcite crystals sell for about $20-30 from fossil and mineral dealers. The larger amounts are in amethyst: Brazilian and Uruguayan amethyst "cathedrals" and clusters sell at retail for roughly $50-200 per kilogram depending on color and form, so a 35 pound cathedral is roughly a $1,000-3,000 piece at a dealer, more at a design gallery and noticeably less on resale.
The price of a geode is set by what is inside and how big it is: the crystal type, the color, the size and sharpness of the crystals, whether the cavity is complete and whether both halves are present. A geode that rattles, crumbles, or turns out solid has little value. Dyed and coated geodes are common and are priced as decor.
Quick answer
- Unopened geodes: about $2-5 each, including Keokuk geodes bought by the box.
- Opened pairs, 2 to 4 inches, clean quartz or calcite: about $15-40. Keokuk with rare inclusions such as millerite or sphalerite: more.
- Amethyst cathedrals and clusters: roughly $50-200 per kilogram at retail, lower on resale. Small amethyst pieces $10-60.
- Dyed pink, blue and purple agate geodes and "aura" coated geodes: about $5-30 as decor.
How to identify and value a geode, step by step
- Feel the weight. A geode is a round rock with a hollow, crystal-lined center. Weigh it in your hand against a solid rock of the same size: a hollow geode feels light for its size. A solid ball of agate or quartz is a nodule, which can still be pretty but is not a geode.
- Look at the outside. Keokuk geodes have a bumpy, cauliflower-like gray or tan skin and are round to slightly flattened. Moroccan geodes are often dark and rounded. Mexican Las Choyas "coconut" geodes are small, round and brown. Amethyst geodes from Brazil and Uruguay are basalt-skinned and usually arrive already opened.
- Listen and tap. Shake it next to your ear. A rattle can mean loose crystals or debris, which lowers value. A dull sound on tapping suggests solid; a hollower sound suggests a cavity.
- Identify the crystals. Quartz forms clear or white six-sided points and scratches glass. Calcite forms blocky or dog-tooth crystals that a steel knife scratches and that fizz in a drop of vinegar. Amethyst is purple quartz. Chalcedony forms smooth, wavy linings without points. Celestite, mostly from Madagascar, forms pale blue blades. Keokuk geodes can hold dolomite, kaolinite, pyrite, sphalerite, goethite and rarely millerite, a brass-colored hair-like mineral that collectors look for.
- Judge the crystals. Sharp, bright, unbroken crystals with good luster, a cavity that is fully lined and a clean color are high grade. Dull, stained, small or broken crystals, and a cavity with muddy filling, bring it down.
- Check for dye or coating. Agate geodes dyed hot pink, purple, teal or bright blue are common decor items, mostly from Brazil. Coated "aura" geodes have a metallic rainbow sheen from a vapor-deposited coating. Gold or silver paint along the rim is decoration. None is natural color.
- Measure. Diameter for small geodes, height and weight for amethyst pieces. Price per kilogram is the norm for amethyst cathedrals and large clusters.
- Keep the pair. If it is opened, keep both halves. Matched halves sell for more than single halves, and a clean break that fits back together is a selling point.
How to crack a geode without ruining it
The way a geode is opened matters to its value. A hammer blow straight on often shatters it into several pieces and breaks crystals. A better home method is to score a line around the middle with a cold chisel, tapping lightly while turning, until it parts. The tool that opens most Keokuk geodes cleanly is a chain-style soil pipe cutter, which squeezes the geode evenly around its middle and splits it into two neat halves; rock shops often offer to crack geodes this way for a small fee. A lapidary saw gives the cleanest flat face and is the right choice for a geode you think may be special, though the saw marks will show. Wrap any geode in a cloth or put it in a sock before striking, and wear eye protection.
What geodes sell for
Prices below are typical sold and dealer prices for natural, undyed geodes as of late 2026. Amethyst asking prices at furniture and design galleries run higher than these.
| Geode | Size | Typical price, as of late 2026 |
|---|---|---|
| Unopened Moroccan or Mexican geode, bulk | 2 to 3 inches | About $2-5 each |
| Unopened Keokuk geode, box lots | 2 to 3 inches | About $2-5 each in boxes of 25 to 30 |
| Opened Keokuk pair, quartz or calcite | 2 to 3 inches | About $20-30 |
| Opened Keokuk pair, good crystals | 4 to 8 inches | About $40-200 |
| Keokuk with millerite, sphalerite or unusual inclusions | Various | Higher; sales are thin and depend on the specimen |
| Las Choyas "coconut" geode pair, Mexico | 2 to 4 inches | About $10-40 |
| Small amethyst geode piece or cluster | Palm-size | About $10-60 |
| Amethyst cathedral, Brazil or Uruguay | 1 to 4 kilograms | Roughly $50-200 per kilogram at retail |
| Large amethyst cathedral, deep color | 15 to 40 kilograms | $2,000-7,000 asked at galleries; resale often well below |
| Celestite geode, Madagascar | Palm-size to fist-size | About $20-150 |
| Dyed agate geode or coated aura geode | Small | About $5-30 |
| Thunderegg, cut and polished, Oregon | 2 to 4 inches | About $10-50 |
The honest picture: most geodes are common and inexpensive, and the fun of breaking one open is a large part of what people pay for. A Keokuk geode from a creek bed in southeast Iowa, where the geode is the state rock, will usually be a pleasant pair of quartz halves worth about $10-30. Amethyst is a real market with real money, but the difference between gallery prices and what a private seller can get back is large. Auction estimates and dealer buy offers for mid-size cathedrals often come in at a fraction of the per kilogram retail figure.
A worked example
Say you find a round, bumpy gray rock about 3 inches across in a creek in northeast Missouri. It feels light. You take it to a rock shop, where it is split with a pipe cutter, and inside are clear quartz crystals about a quarter inch long, with a few small brown calcite rhombs, and the cavity is fully lined. That is a Keokuk geode in good condition, and the pair is worth roughly $20-35. Had the cavity held a tuft of brassy, hair-like crystals, it could be millerite, which collectors seek; that would be worth showing to a Keokuk specialist or mineral club before pricing. Had it been solid all the way through, it would be a nodule worth a few dollars at most.
What moves the price
| Factor | Effect on price |
|---|---|
| Fully lined cavity, sharp bright crystals, both halves | The baseline for the top of each range |
| Only one half | Deduction of about 30-50 percent |
| Shattered or broken in pieces | Deduction of 50-90 percent |
| Rattling loose crystals or mud inside | Deduction of 30-60 percent |
| Rare inclusions (millerite, sphalerite, pyrite, goethite in Keokuks) | Adds a premium for collectors |
| Deep, even purple in amethyst | Two to three times pale or patchy amethyst |
| Calcite or goethite accents on amethyst | Adds interest and value |
| Large size with good form | Raises value faster than weight alone |
| Dyed or coated | Priced as decor; no natural premium |
| Cement base or polished rim | Common on amethyst; fine if natural crystals are intact |
Fakes, dye and treatments
Geodes are rarely faked from scratch because real ones are cheap. What you will see is dye, coating and enhancement. Brazilian agate geodes are often dyed bright pink, purple, teal or blue; the color is uneven, deepest where the stone is porous, and it can fade in sunlight. "Aura" or "titanium" geodes are real quartz with a thin metallic coating that gives a rainbow sheen, and they are sold for their look. Some amethyst is heat-treated to turn yellow or orange and is sold as citrine; natural citrine geodes are rare, and an orange "citrine cathedral" is almost always heated amethyst. Glued crystals in an otherwise empty cavity, and resin-filled cracks in large amethyst pieces, show up under magnification as shiny glue lines. More on telling amethyst color from treatment is in our guide on how to tell if amethyst is real.
How WorthPic reads geode photos
WorthPic runs on the newest and most capable AI model available, tuned for exactly this kind of identification. From photos of the outside and the opened cavity, it reads the skin texture and shape to suggest the source, identifies the main crystals and any accessory minerals, judges how complete the lining is and how sharp and bright the crystals are, and looks for the color patterns that point to dye or coating. For amethyst it reads color depth and evenness. It then gives an honest value range for what the photos show. What it cannot know from a photo is weight, whether a rock is hollow before it is opened, or whether crystals have been glued. It identifies and estimates. It does not authenticate, grade or appraise. For an unusual mineral inside a Keokuk geode, or a large amethyst piece, a mineral dealer or local mineral club is the right next stop.
Common mistakes
- Hitting a geode straight on with a hammer. It usually shatters. Use a chisel, a pipe cutter or a rock shop.
- Assuming every round rock is a geode. Most are solid nodules or ordinary concretions.
- Believing bright pink or blue crystals are natural. They are dyed or coated.
- Pricing a resale amethyst at gallery prices. Retail and resale are far apart.
- Washing a geode with crystals that dissolve. Calcite is attacked by vinegar and acid cleaners; use plain water and a soft brush.
- Separating the halves. Matched pairs sell better.
- Collecting in state parks where it is not allowed. Several Midwest parks have geodes and rules against taking them.
What to photograph
- The outside of the geode, whole or both halves, with a ruler for scale.
- The open cavity straight on in daylight, sharp enough to see crystal shapes.
- A close photo of any unusual mineral inside, in focus.
- For amethyst, the crystals in daylight, not under warm room lights that shift purple.
- The back and base of an amethyst cathedral, showing any cement or repairs.
- The weight on a scale for any amethyst piece.
When to get it looked at in person
Unopened geodes and ordinary quartz pairs do not need an expert. If you want a geode opened cleanly, a rock shop with a pipe cutter or saw is the best help. A local rock and mineral club is the right place to identify an unusual mineral, and members can tell millerite from pyrite on sight. For a large amethyst cathedral you plan to sell, compare sold prices, not gallery asks, and approach mineral dealers who buy, since they will make an honest offer at wholesale. For geodes lined with banded agate, see our agate value guide, and for other stones from the same creek or field, our guide on how to identify valuable rocks walks through the home tests.