Rock · Igneous rock
Peridotite
A rock is a mix of minerals, so it has no single hardness or streak. Scratching it tests whichever grain you happen to touch. Stoneye names the rock from the photo and lets you test the minerals inside it.
StoneyeHave a stone like this?
Photograph it with Stoneye for a shortlist, then narrow it down with the same tests. The app tells you when it is not sure instead of guessing.
Download on the App Store