Who makes it
Stoneye is made by Ahmet Karaca under Akaya Labs, a one-person software studio in Rize, Türkiye. I'm a software developer, not a geologist. That is why the answers come from published references rather than from my judgment, and why the app says so when it can't tell.
Where the data comes from
The table holds 201 minerals and 26 rocks. Each record names the reference it was checked against, such as Mindat or the Handbook of Mineralogy, and the page shows that name.
Where a reference gives a range, the whole range goes in the table. It is never narrowed to make identification easier. A value the reference doesn't give stays blank and rules nothing out. Names in other languages come from Wikidata; where no name exists in a language, the English one is shown rather than an invented one.
How an answer is reached
A vision model looks at the photo and proposes a shortlist. It does not choose the answer. Eliminating candidates, picking the next test and giving the final result is ordinary code on your phone, so the same answers always lead to the same result.
What was measured, and the limits
Tested against every record, the engine gave 0 wrong answers. That measures the engine against its own table, not real stones. The photo step is separate: on a set of 9 labelled rock photos it named 7 correctly, and that sample is small.
Only 30 of the 201 minerals come down to a single name with home tests, and about 4% of all pairs can't be separated that way. For anything that matters, such as value, safety or a health concern, ask a qualified geologist or a lab.
Found a mistake?
Write to support@stoneye.app with the mineral and the reference you are looking at. Corrections go into the table, and the app and this site both read from it.