The best free rock identifier apps, compared on what is checkable

How this comparison works

Every list of rock identifier apps faces the same problem: the thing readers most want ranked — accuracy — is published by nobody. Vendors do not release benchmark results, and no independent test with a controlled photo set exists for this category. Lists that rank accuracy anyway are ranking their own impressions.

So this page compares what can be checked from public record on a stated date: which platforms each app ships on, whether the developer maintains a companion website, what each store listing says the free tier includes — read on 2026-09-16 — and how large the app’s search footprint is: referring domains and search traffic of its store cards, measured with Ahrefs on 2026-08-07. Footprint is a proxy for installed base and longevity, not for quality, and it is labeled as exactly that.

The four apps people actually install

1. Rock Identifier: Stone ID

The category incumbent, on iOS and Google Play, published by Next Vision. Its store cards are the strongest asset in the niche: the App Store card alone carries 1,864 referring domains, and the Play card draws about 6,206 US search visits a month — both figures from our 2026-08-07 Ahrefs measurement, and both larger than any independent rock website we measured. Scale of that kind implies a mature recognition pipeline and years of accumulated training photos; it implies nothing about whether the free tier will identify your stone before asking for a subscription.

2. Rock & Crystal Identifier

A Google Play release by slsolutions with no iOS version and no companion website. The name leads with crystals, which matches how it frames results. Android-only distribution halves its addressable audience, and the absence of any web presence means the store page is the entire public record — read it with the dates in mind, because store descriptions are marketing copy, not documentation.

3. Stone Identifier Rock Scanner

Another Play-only app with no website. Its store card drew triple-digit monthly search visits in our measurement — a fraction of the incumbent’s footprint. Smaller footprint is not a verdict: it can mean a newer app or a worse one, and nothing public distinguishes the two. What it does mean is fewer years of user photos behind the model, which in this category is the training data.

4. Rock Scanner: Mineral ID

The mirror case: iOS-only, published by Manuel Worlitzer, with no Android version and no companion website — on 2026-09-16 the listing’s developer link opened an app-ads.txt file rather than a site. When this comparison was first written the same listing was titled Rock Identifier: AI Scan; by 2026-09-16 it carried its current name. It is the newest of the four, released in June 2025. It is also the only one whose store page states that identification works offline. The photo-classification approach is the same as the rest of the field; as with any young app, the checkable record is thin, which cuts both ways.

The comparison in one table

What each app gives free before the paywall

Every one of the four installs free, and none of them is free to use without limit. What the store pages say about the free tier differs, and this table records it as read on 2026-09-16 — store descriptions are marketing copy that changes without notice, so treat each cell as dated evidence rather than a promise.

The practical reading is short. If you want to identify a handful of stones once, Rock & Crystal Identifier is the only listing that states a free count up front. If you want to judge an app properly, start a trial only after you have run the accuracy check below on stones you already know, and note the renewal date the moment the trial begins.

Which rock identifier app is most accurate?

Nobody knows in any tested sense. None of the four developers publishes accuracy measured on a controlled set of photos, and no independent benchmark for this category exists as of 2026-09-16 — the accuracy lines on store pages are claims, not measurements. You can run a fair comparison yourself in about twenty minutes, with stones whose identity you have already confirmed.

The result is accuracy on your kind of stones, which is the only accuracy that matters for your finds. It says nothing about stones you cannot identify yourself, and that is exactly where a physical check still has to finish the job: the confirming tests for the set above are in the mineral identification chart and the streak test, and the slag-versus-obsidian trap is settled in what is slag glass.

The free web identifiers nobody lists

The strangest fact in this niche is who ranks. The top result for crystal identifier in our 2026-08-07 measurement was identifyrock.net — a small web tool with zero referring domains to the ranking page and about 1,944 monthly visits — with a similar browser tool right behind it. Browser identifiers are worth knowing about: free, no install, adequate for a one-off upload at a desk. Their limits are structural — no offline use on a beach, no collection log, and usually a bare name with no confirming checks — which is the standing argument for an app, laid out from our side on the rock identifier page.

Where Gleamite fits

Gleamite is our own app, so it does not appear in the ranking above — including your own product in your own comparison table is how every other list in this niche works, and it is exactly what makes them unreliable. What we will state is design intent: identification runs on-device and offline, every match ships with the physical check that confirms it, and the app declines to price stones. The identification method itself is public on this site — the rock identification chart and the crystal identifier checks are the same logic the app automates, and the gem identifier page documents where we think photo identification honestly ends.