Rocks & minerals · Rockr
How to identify rocks and crystals from a photo
Photograph the rock clean, dry, and in daylight, next to a coin for scale — then let the visual features speak: color, luster (metallic? glassy? waxy?), crystal habit (cubes? needles? layers?), and any visible grain or banding. Rockr reads those from your photo and returns the most likely rocks or minerals with the features that distinguish each candidate.
A photo honestly answers most casual finds — beach pebbles, garden quartz, the sparkly thing from a hike. For the rest, two kitchen-table tests break the ties: a streak test (scrape it on unglazed ceramic and look at the powder's color) and a scratch test against a steel knife tip for hardness. The app tells you when a tie needs them.
Photograph minerals like a collector
Wet rocks lie. Water saturates color and fakes a polish, which is why riverbed finds disappoint at home — so shoot dry. Indirect daylight beats sun: harsh light blows out the surface detail that separates, say, calcite's pearly faces from quartz's glassy ones. Get one shot of the overall piece and one close-up of the most crystalline face or the freshest broken surface.
A fresh break matters more than people expect. Weathered surfaces all converge on the same dull brown; the inside face shows the true color, luster, and grain. If a corner is already chipped, photograph the chip.
The features that do the identifying
Color is the feature everyone leads with and the least reliable — quartz alone comes in a dozen colors. Luster and habit carry more weight: metallic luster narrows you to a small club (pyrite, galena, magnetite and friends); perfect cubes say halite or pyrite or fluorite; visible banding says sedimentary or metamorphic story, not mineral crystal. Rockr weighs the features in that order, which is why its second suggestion is sometimes the right one when color misleads.
Weight is a feature you can't photograph but can report: a rock that feels heavy for its size points at metal ores; suspiciously light points at pumice or industrial slag — the most common "meteorite" false alarm there is.
Value, and the finds worth a second look
Most finds are common quartz, feldspar, or calcite — worth exactly the joy of knowing their names. The ones worth further attention: anything that scratches glass AND shows crystal faces, anything genuinely metallic that isn't rusty, and anything a magnet grabs that isn't obviously man-made. Rockr flags these, and for a suspected meteorite or gem, the result points you to what a professional would check next.
Rockr AI: Rock Identifier
That stone in your pocket has a name. Rockr identifies rocks, minerals, and crystals from a photo.