Rock Identify: Identify Rocks by Photo

Begin with the specimen you actually have, rather than a similar picture found online. A photo-based rock identifier needs a clear view of its surface. Place it against plain paper or another quiet background, use indirect daylight, and tap the screen to focus on the rock.

Different angles are more useful than several nearly identical shots. Include the overall shape, a close-up of grains or bands, and an existing edge. Keep all views on the same specimen so separate materials are not mistaken for one rock.

Add observations you can describe confidently: where you found it, approximate size, visible layers, or a smooth versus rough surface. In live mode, those notes provide context for the photo analysis. Avoid filters, strong glare and guesses presented as facts; the photo guide explains what to show.

Photo identification focuses on visible clues such as grain size, banding, surface texture and the shape of a specimen. A speckled surface gives different information from flat layers or glassy edges. Color helps describe a find, but several unrelated materials can share the same color.

The result brings a possible name together with the reasons and uncertainties behind it. Compare those observations with your own rock before accepting the label. A missing detail is a reason to take another view, not proof that a candidate is correct.

The reference cards describe typical properties of possible materials and link to educational sources. Those properties have not been measured on your specimen. The page keeps this general information separate from what the uploaded photographs actually show.

A shiny black piece illustrates why several clues matter. Natural volcanic glass and manufactured glass can look similar in a photograph; a dark color alone does not distinguish them. A pale, grainy specimen presents a different problem: visible grains may suggest sandstone, but a photograph may not resolve the grain boundaries needed to compare it with quartzite. Treat those alternatives as questions to investigate. Photograph an existing edge and note whether the pattern continues across it, without breaking or scratching the specimen. If the image cannot show the distinction, an uncertain answer is more useful than a confident guess.

A suggested match may be a rock type or a mineral name. Rocks can contain several minerals, while a mineral has its own composition and structure. Quartz is a mineral; granite is a rock that can contain quartz. Read the category as carefully as the name.

Igneous rocks form as molten material cools. For a granite or basalt suggestion, compare the grain size and overall texture rather than color alone. A coarse mixture of visible crystals and a fine textured surface provide different starting points for comparison.

Sedimentary rocks form from accumulated material or deposits. With a sandstone suggestion, look for grains and layering. Metamorphic rocks have been changed by heat or pressure; for a gneiss or slate suggestion, examine bands or flat surfaces. These clues guide comparison but do not prove an identity.

Learn the basic distinctions in the National Park Service rock guide and its mineral reference.

No photo-based tool can guarantee a correct name from a photograph. Weathered surfaces, polished stones, poor lighting and similar looking materials can obscure the features needed to distinguish candidates. A detailed explanation is useful, but it is not independent confirmation of the suggested identity.

Check the availability notice beside the upload controls before starting. When identification is enabled, the tool uses AI photo analysis and presents each result as tentative. If analysis is paused, you can still read this guide and compare visible features yourself. No measured accuracy percentage is claimed here.

When a name matters, take the specimen and its location notes to a qualified geologist or appropriate laboratory. A photograph cannot measure hardness, density or chemical composition. Start with another angle or a ruler for scale; do not damage an unknown specimen just to complete an online check.

Rock Identify works in your browser without registration. The upload panel shows the available daily allowance, and a result shows whether a free follow-up remains. A completed but uncertain analysis uses an identification; a technical failure does not. Repeatedly pressing a button does not create extra completed analyses.

Your conversation belongs to the current specimen. Ask which visible feature would separate two candidates, or what a suggested material is typically used for. Replies should explain uncertainty, especially when a question concerns treatments, authenticity or a possible lookalike.

Unsaved photos, results and conversations become unreadable after 24 hours. A specimen saved to an account collection is stored privately until you delete it or the account. You can reopen the most recent valid temporary result in the same browser, and deletion does not renew the daily allowance. Read the privacy explanation for the difference between access expiry and subsequent storage cleanup.

How your photos and results are handled · Read the usage limitations