Free Rock, Mineral & Fossil Identifier

Identify, compare, and verify

• Quick ID by properties — Narrow candidates without a photo or account.
• Rock and mineral field workflow — Build a defensible shortlist from context, texture, and physical properties.
• Printable identification chart — Compare common rocks, minerals, field clues, and safer next checks.
• Identification methodology — Review GeoMiner's evidence, uncertainty, privacy, and safety standards.
• Specimen safety guidance — Review dust, fibres, toxic elements, radioactivity, and handling limits.
• Black Metallic Minerals: Field Identification Guide — Compare common black minerals with a metallic lustre using magnetism, streak, hardness, density, and cleavage before choosing an identification.
• Green Minerals: How to Tell Them Apart — Identify common green minerals by comparing hardness, streak, cleavage, habit, host rock, and reaction to dilute acid—not colour alone.
• Minerals That Scratch Glass: Hardness Guide — Learn what a glass scratch test means, which common minerals may scratch glass, and how to avoid confusing a powder mark with a true scratch.
• White Minerals: Quartz, Calcite, Feldspar and Look-Alikes — Separate common white and colourless minerals with hardness, cleavage, acid reaction, taste-free testing, and crystal form.
• Vesicular Rocks: Basalt, Scoria and Pumice — Identify rocks with gas-bubble cavities by comparing colour, density, vesicle walls, composition, and volcanic context.
• Banded Rocks: Gneiss, Iron Formation and Layered Look-Alikes — Interpret banded rocks by separating metamorphic mineral segregation, sedimentary bedding, flow banding, veins, and weathering patterns.
• Red Minerals: Garnet, Hematite and Look-Alikes — Compare common red, reddish-brown, and scarlet minerals using streak, hardness, lustre, habit, density, and geologic setting rather than colour alone.
• Blue Minerals: Azurite, Kyanite, Sodalite and Look-Alikes — Narrow common blue minerals with streak, hardness, cleavage, crystal habit, host rock, and colour distribution instead of relying on hue alone.
• Metallic Minerals: A Safe Field Identification Guide — Separate common metallic-looking minerals with colour, streak, hardness, magnetism, cleavage, density, tarnish, and host-rock evidence.
• Glassy Rocks: Obsidian, Volcanic Glass and Slag — Identify glassy rocks and look-alikes by comparing fracture, bubbles, flow structures, inclusions, weathering, density, and field context.
• Foliated Metamorphic Rocks: Slate, Phyllite, Schist and Gneiss — Separate common foliated metamorphic rocks using grain size, cleavage, sheen, mineral alignment, compositional banding, and metamorphic context.
• Porphyritic Rocks: How to Identify Phenocrysts and Groundmass — Interpret porphyritic texture by comparing phenocryst minerals, groundmass grain size, vesicles, alteration, and intrusive or volcanic field relationships.
• Gold Look-Alikes: Pyrite, Chalcopyrite, Mica or Real Gold? — Identify common gold look-alikes by comparing deformation, streak, hardness, crystal shape, sheet cleavage, tarnish, and density before considering an assay.