Somewhere right now, a person is standing in a creek bed holding a heavy black stone and wondering if they just found a meteorite. (Statistically: they found magnetite. But that’s the fun of it.)
What's This Rock?exists for that moment. This site was inspired by the thousands of identification questions asked every day in online rockhounding communities like Reddit’s r/whatsthisrock — the same handful of wonderful, recurring mysteries: Is this a meteorite? Is this obsidian or slag? Is this gold or pyrite? Should I crack this open?
Rather than answering one photo at a time, these guides teach the method: the streak test, the hardness scale, luster, density, and context. With a porcelain tile, a steel knife, and ten minutes, you can identify most of what you’ll ever pick up.
This site is an independent project and is not affiliated with Reddit or the r/whatsthisrock community. For tricky specimens, nothing beats a local geology department, a rock and mineral club, or a natural history museum’s identification day.