How Much Is a Petoskey Stone Worth?
Petoskey Stone value: about $6–$20 per pound unpolished; $8–$55 each polished; jewelry $25–$250
Petoskey stones are Michigan's state stone: pieces of a fossil colonial coral that lived in warm, shallow seas some 350 million years ago. Most beach finds are worth a few dollars. Michigan shops sell unpolished stones for about $6–$20 a pound, and an online seller asks $4–$16 for single rough stones. Polishing adds most of the value: polished stones sell for about $8–$55 each depending on size and pattern, and pieces set in sterling silver for $25–$250.
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Petoskey Stone Prices by Type (2026)
Retail asking prices from Michigan gift shops and online Petoskey stone sellers, September 2026.
| Type | Details | Typical price |
|---|---|---|
| Unpolished stones by the pound | Raw stones from about 1 to 4 inches; the pattern shows when wet | Typical price: $6–$20 per pound |
| Single rough stones | Unpolished stones sold by weight, 1 oz to 4 oz | Typical price: $4–$16 each |
| Small stones and chips | Carded stones with a history card, polished party-favor chips in bulk, polished slab chips | Typical price: $3–$10 each |
| Fully polished stones | Hand-picked by price point; about $10 buys a 1–2 inch stone | Typical price: $8–$55 each |
| Polished stones by weight | 1 oz, 3–4 oz and 7–8 oz stones at one online seller | Typical price: $19; $31–$37; $55–$90 |
| Partially polished stones | One face polished, the back left natural | Typical price: $15–$60 each |
| Slabs, tiles and decor | Unpolished slabs by the pound; 12-inch tile sheets of about 16 slabs; slab coasters | Typical price: $25/lb slabs; $62–$90 decor |
| Jewelry | Stud earrings and small pendants up to large sterling silver pendants and men's rings | Typical price: $25–$250 |
These are shop asking prices for stones picked, cut and polished for sale. An unpolished beach stone is worth a few dollars, since shops sell raw stones for about $6 a pound. No auction or wholesale prices could be verified.
What Makes a Petoskey Stone Worth More
The factors buyers and dealers actually price on.
Polish
Polishing turns a $6-a-pound rock into an $8–$55 stone. One Petoskey shop says each of its stones is hand-polished by local makers.
Size
Price rises with weight: one online seller asks about $19 for a polished 1 oz stone, $55 for 7 oz and $90 for 8 oz.
Pattern and color
Every stone differs in pattern and color, and shops hand-pick the best-looking stones for each price point. Raw stones are sold without any promise of how much pattern shows, beyond that it shows when wet.
Soundness
Some stones are too porous or have too much clay, quartz or pyrite to take a good polish, according to Michigan's geological survey.
Michigan origin
Similar Hexagonaria corals occur in Iowa, Ohio, other states and overseas and are hard to tell apart by eye, so buyers rely on the seller for where a stone was found.
Workmanship
Setting a stone in sterling silver lifts it into the $25–$250 range, and a 12-inch tile of about 16 slabs sells for about $90.
Is It a Petoskey Stone? Quick Checks
A Petoskey stone is fossil coral in limestone. These checks separate it from other fossil corals and from printed look-alikes.
- 1
Wet it
A dull, dry stone can hide the pattern. Splash water on it or walk the wet surf zone; the pattern shows best when wet.
- 2
Six-sided cells with dark centers
Look for a honeycomb of hexagons, each with a dark center. Michigan's geological survey describes a gray-brown stone with dark circles in the middle of the hexagons.
- 3
Cell size
If the openings are tiny and look like lace draped over the rock, it's more likely a Charlevoix stone (Favosites).
- 4
Softness
It's mostly calcite, about Mohs 3, so it scratches easily and can be polished by hand with sandpaper. Shops warn that long tumbling can wear it away.
- 5
Acid test
Limestone fizzes with a drop of dilute acid; household vinegar works, just more slowly. Test a hidden spot, not a polished face.
- 6
Coatings
Some stones and slabs are sealed with a clear spray or resin to bring out the pattern. Ask whether a piece is polished or coated.
- 7
Printed designs
Many gift items carry a 'Petoskey pattern' that is printed or molded, not fossil. Read the listing before paying stone prices.
Common look-alikes
Charlevoix stone (Favosites)
A tabulate coral whose openings are much smaller than a Petoskey stone's and look like lace draped over the rock.
Hexagonaria from elsewhere
At least seven Hexagonaria species occur in Michigan, and related corals are found from Iowa to Germany and Asia. They are hard to tell apart on casual inspection.
Other Michigan fossil corals
Pipe coral (Syringopora), chain coral (Halysites) and horn corals turn up on the same beaches.
Printed 'Petoskey pattern' items
Tiles, magnets, keychains and stickers with a printed pattern are souvenirs, not fossils.
Not sure what you have? Identify it free from a photo.
Collecting Rules to Know
- On Michigan state-owned land, including state parks, it's unlawful to remove more than 25 pounds of rocks, minerals or invertebrate fossils per person per year, and only for non-commercial hobby use.
- The limit covers Great Lakes bottomland too: in 2015 DNR officers confiscated a 93-pound Petoskey stone pulled from Lake Michigan near Northport. Check for posted local rules at each park or beach.
- Sleeping Bear Dunes National Lakeshore is off-limits: removing stones there is illegal under federal law.
- Get permission before collecting on private land.
How to Sell a Petoskey Stone
- Be realistic: Michigan gift shops sell raw stones for about $6–$20 a pound, so most beach finds are worth a few dollars each.
- Polishing adds the most value. Michigan's geological survey describes hand polishing with 220, 400 and 600 grit wet sandpaper and a polishing compound.
- Outlets include Michigan gift shops, rock shows and online marketplaces. List the weight and size, and say whether a stone is polished, coated or unpolished.
- DNR rules limit stones from Michigan state land to non-commercial hobby use, so only sell stones from private land (with permission) or ones you bought.
- In the Ruby Glint app you can list Petoskey stones in the marketplace and chat directly with buyers.
Identify, value and sell your finds
Scan a specimen for its name and a value range, keep it in your collection, and list it in the marketplace to chat with buyers.
Petoskey Stone Value Questions
Get answers to common questions about rock identification, rockhounding, and using our platform.
Most beach stones are worth a few dollars; Michigan shops sell unpolished stones for about $6–$20 a pound. Polished stones sell for about $8–$55 each depending on size and pattern, and sterling silver jewelry for $25–$250.
Yes. One online seller asks about $19 for a polished 1 oz stone and $55 for a 7 oz stone, against $4–$16 for rough stones of 1–4 oz.
Wet it and look for a honeycomb of six-sided cells, each with a dark center. It's a fossil coral in limestone: soft, mostly calcite, and it fizzes with dilute acid or vinegar.
Both are fossil corals. Petoskey stones (Hexagonaria) have larger six-sided cells with dark centers; Charlevoix stones (Favosites) have much smaller openings that look like lace.
On Michigan state land, including state parks and Great Lakes bottomland, you may take up to 25 pounds a year for non-commercial hobby use. Collecting is illegal at Sleeping Bear Dunes National Lakeshore, and private land needs permission.
The source rock is around Little Traverse Bay near Petoskey, but glaciers spread the stones across Michigan. They turn up on beaches from Frankfort on Lake Michigan to Fort Gratiot County Park on Lake Huron, and in sand and gravel pits.
Yes. Its softness makes hand polishing with wet sandpaper and a polishing compound practical. Go easy in a rock tumbler, because shops warn soft stones can wear away.
Related guides
Sources
Price ranges come from published dealer prices, auction results and the sources below, checked September 25, 2026. Prices move, so treat them as a guide.
- Michigan EGLE: Michigan fossils and how to find them
- Michigan EGLE: Rock and mineral identification
- Michigan Geological Survey: The Petoskey Stone (pamphlet)
- Michigan DNR: State land rules for parks and recreation areas
- National Park Service: Esch Beach, Sleeping Bear Dunes
- Field Museum: Beachgoer's guide to Lake Michigan fossils and rocks
- CBS Detroit: State confiscates huge Petoskey stone (2015)
- The Petoskey Stone Shop: Unpolished Petoskey stones
- Sturgeon River Pottery: Fully polished Petoskey stones
- The Petoskey Stone: Polished Petoskey stones by size