Identify Any Rock
Through Conversation

Send a photo and tell me where you found it. I'll work through the texture, grain size, and visible mineral content to classify it:

• Igneous: Granite, basalt, obsidian, pumice, gabbro — formed from cooling magma or lava
• Sedimentary: Sandstone, limestone, shale, conglomerate — deposited in layers over time
• Metamorphic: Marble, slate, gneiss, quartzite, schist — transformed by heat and pressure

I'll note when a rock sits on a boundary — nature doesn't always follow clean categories.

Minerals have diagnostic properties. I'll ask about or analyze from your photo:

Whether you collect crystals or found a sparkly stone and want to know if it's special:

• Gemstone-quality assessment — though a proper appraisal requires a gemologist with tools
• Crystal habit descriptions (prismatic, tabular, botryoidal, druzy, etc.)
• Common vs. rare varieties and what makes the difference
• Where specific crystals are typically found in the world
• How to tell natural from synthetic or treated stones

I can give you context on collectible value, but I'm not a certified appraiser. For high-value stones, always get a professional evaluation.

Every rock has a story. I enjoy explaining the journey:

• How a specimen formed — volcanic eruption, slow crystallization, metamorphic compression, or sedimentary deposition
• What geological environment produced it (hydrothermal vents, pegmatites, riverbeds, cave systems)
• Age context — are we talking millions or billions of years?
• Regional geology — if you tell me where you found it, I can narrow identification based on local formations

Photos only go so far. When I'm not confident, I'll suggest hands-on tests you can try:

• Scratch test: Fingernail (2.5), copper coin (3.5), steel nail (5.5), quartz (7)
• Acid test: Vinegar or dilute HCl on calcite and limestone — watch for fizzing
• Streak test: Rub on the unglazed back of a porcelain tile
• Magnet test: Magnetite and some meteorites will attract a magnet
• Heft test: Does it feel heavier or lighter than expected for its size?
• UV light: Some minerals fluoresce under shortwave or longwave UV

It depends on the specimen and photo quality. Many common rocks and minerals have distinctive visual features (color, crystal habit, luster) that make photo ID reliable. But some minerals look nearly identical in photos — that's when I'll suggest hands-on tests like scratch, streak, or acid tests. I always flag my confidence level.

Natural daylight, a clean background, and something for scale (a coin, your finger). Multiple angles are better than one. Show the fresh surface if you've broken it, and capture any visible crystal faces or textures. A wet surface can also reveal details that a dry surface hides.

I can give you general context — whether a mineral is common or rare, whether specimens like yours typically have collectible or gemstone value, and what factors affect pricing (clarity, size, color, locality). But I'm not a certified appraiser. For anything you think might be genuinely valuable, take it to a gemologist or mineral dealer for a proper evaluation.

A mineral is a naturally occurring, inorganic solid with a definite chemical composition and crystal structure — like quartz (SiO₂) or calcite (CaCO₃). A rock is an aggregate of one or more minerals. Granite, for example, is a rock made of quartz, feldspar, and mica. I'll help you understand which you're looking at and why it matters.

I'm an AI with deep training in geology and mineralogy. I can analyze your photos and discuss specimens with the kind of detail you'd expect from a knowledgeable rockhound or geology student. I'm not a replacement for laboratory analysis or professional geological surveys — but for casual identification, learning, and collection building, I'm a solid starting point.