The shortlist
4 things that do it.
A browser tool and matching iPhone and Android app (AI Rock ID) that name a rock, mineral, crystal, gemstone or fossil from a photo, with Mohs hardness clues and a rough value range.
- Free
- One scan per day is free on the site; the app is free to download, includes extra daily scans, and has optional unlimited identification (Rock Identifier site).
- Paid
- from $4.99 per week or $29.99 per year (App Store in-app purchases, US listing)
- Best at
- A quick free first opinion in the browser, with no install, on a common rock from a clear photo.
- The catch
- The site says one scan per day is free. Its own page says accuracy drops on weathered, polished, dyed or matrix-embedded samples and on lookalikes, and that it is not for certified gemstone appraisal or professional lab identification.
- web
- ios
- android
An app and free online tool that identify rocks, minerals, crystals and gemstones from a photo and return name, rock type, hardness and other geological details.
- Free
- Free identification with basic features; premium adds unlimited identifications, detailed geological reports and collection management (Ruby Glint FAQ).
- Paid
- price not checked
- Best at
- Free browser identification plus an app with a saved collection and a rockhounding locations map.
- The catch
- The 90%+ accuracy figure is the vendor's own claim for common rocks and minerals. Premium pricing is not shown on the pages we read.
- web
- ios
- android
An Android app that identifies a crystal, rock or mineral from a photo and returns chemical formula, Mohs hardness and classification, with a saved collection and learning tools.
- Free
- Free to download with 5 free rock identifications; after that Stone Snap Pro is $4.99 per month with a 3-day free trial (Stone Snap FAQ).
- Paid
- from $4.99 per month (Stone Snap Pro)
- Best at
- Android users who want geology details, a collection with GPS coordinates and a magnetic detector in one app.
- The catch
- Android only. Identification needs an internet connection because photos are processed on Google's servers. Prices are in US dollars.
- android
A free, volunteer-run mineral and locality database with property searches, photos, an identification request forum and a learning centre.
- Free
- The site says its supporters help keep Mindat free and available to everyone; a free account is offered.
- Paid
- from Free
- Best at
- Checking a guess from an app against mineral data, or asking people to identify a specimen.
- The catch
- It is a reference site, not a photo-recognition app: you search by properties or post an identification request.
- web
How they compare
Which one suits you, and why.
If you want it free with no download
Rock Identifier suits this need. You upload or take a photo in the browser and get a name, Mohs hardness clues and a rough value range, with nothing to install. It is best for a quick free first opinion on a common rock from a clear photo. It also covers minerals, crystals, gemstones and fossils, and there is a matching iPhone and Android app (AI Rock ID).
The limit is the allowance. The site says one scan per day is free. The app is free to download and includes extra daily scans, with optional unlimited identification. The vendor's own site does not state what unlimited identification costs. The US App Store listing shows in-app purchases of $4.99 weekly and $29.99 yearly, and prices may differ by country. If you have a pocketful of stones to identify, expect to spread them over several days or use the app.
If you want a free tool and an app from one vendor
Ruby Glint suits you if you want to start in the browser and move to a phone later. The online tool is free and needs no download. The app adds saved history, market value estimates and a map of 260,000+ rockhounding locations, which helps if you go out looking for stones. It returns the name, rock type, hardness and other geological details.
What you give up is clarity on cost. Premium adds unlimited identifications, detailed geological reports and collection management, but we did not find a premium price on the pages we read, so it is not verified. The vendor also claims 90%+ accuracy for common rocks and minerals and 6,000+ rock types. Both figures are the vendor's own and we did not test them.
If you are on Android and want a clear price
Stone Snap is an Android app that gives 5 free identifications. After that, Stone Snap Pro is $4.99 per month with a 3-day free trial, and Pro unlocks unlimited identifications. Each result includes the chemical formula, Mohs hardness and classification. The app also has a saved collection with GPS coordinates, learning tools and a magnetic detector.
It is Android only, and it needs an internet connection to identify, because photos are processed on Google's servers. Saved collections stay on the device. Prices are in US dollars.
If you want to check a result against a reference
Mindat is a free, volunteer-run database of 6,240+ mineral species, with data on properties, chemistry and structure, plus photos and a learning centre. It does not recognise photos. You search by properties or post an identification request in its forum. That makes it useful when an app has given you a guess and you want to see whether it holds up.
You give up speed. Nothing comes back instantly, because you are reading, searching or waiting for people to reply.
When paying is worth it
Pay only if you scan often. Stone Snap Pro is $4.99 per month for unlimited identifications, and the free allowance on Rock Identifier's site is one scan per day. If you identify a stone now and then, the free options may be enough. If you are sorting a large box of finds, a paid plan is more likely to be worth it.
What to watch for
The catches worth knowing first.
Rock Identifier says accuracy is high for distinctive specimens such as granite, basalt and quartz, but drops on weathered, polished, dyed or matrix-embedded samples and on lookalikes such as calcite and quartz. Its own page says the tool is not for certified gemstone appraisal, meteorite confirmation, hazardous mineral safety decisions or professional lab identification. If money or safety depends on the answer, treat an app result as a starting point only.
On pricing, Ruby Glint does not show its premium price on the pages we read, so check the price in the store listing before you subscribe. Stone Snap's Pro plan starts with a 3-day free trial and then costs $4.99 per month, so cancel before the trial ends if you do not want it.
Stone Snap cannot identify a new photo offline, so check your signal before you rely on it away from home.
The same shortlist, as a table
| Thing | Free tier | Paid from | Platforms | The catch |
|---|---|---|---|---|
| Rock Identifier (AI Rock ID) | One scan per day is free on the site; the app is free to download, includes extra daily scans, and has optional unlimited identification (Rock Identifier site). | $4.99 per week or $29.99 per year (App Store in-app purchases, US listing) | web, ios, android | The site says one scan per day is free. Its own page says accuracy drops on weathered, polished, dyed or matrix-embedded samples and on lookalikes, and that it is not for certified gemstone appraisal or professional lab identification. |
| Ruby Glint rock identifier | Free identification with basic features; premium adds unlimited identifications, detailed geological reports and collection management (Ruby Glint FAQ). | not checked | web, ios, android | The 90%+ accuracy figure is the vendor's own claim for common rocks and minerals. Premium pricing is not shown on the pages we read. |
| Stone Snap | Free to download with 5 free rock identifications; after that Stone Snap Pro is $4.99 per month with a 3-day free trial (Stone Snap FAQ). | $4.99 per month (Stone Snap Pro) | android | Android only. Identification needs an internet connection because photos are processed on Google's servers. Prices are in US dollars. |
| Mindat | The site says its supporters help keep Mindat free and available to everyone; a free account is offered. | Free | web | It is a reference site, not a photo-recognition app: you search by properties or post an identification request. |
How we checked
What we read, and what we haven't tested yet.
On 2026-10-09 we read the Rock Identifier website, Ruby Glint's rock identifier page and its free online tool page, the Stone Snap website and the Mindat homepage and about page, plus the AI Rock ID listing on Apple's App Store (which lists weekly and yearly in-app purchases, while the vendor's own site states no price). Mindat's pages were fetched through a fallback fetcher after a direct request returned a block. Ruby Glint's pricing page does not exist at the address we tried, so its premium price is not verified. Nothing was tested hands-on.
If none of these fit
The manual way.
Mindat's identification request forum lets people look at your specimen, and its property search works without a photo. Rock Identifier's own page recommends a quick scratch, streak, magnet or dilute acid test when candidate minerals overlap. For other things you might want to identify, see our pages on an app to identify coins, a website to identify antiques and an app that identifies plants.