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Crystal Identification Chart and Guide
Crystal identification is mineral identification, not colour matching. Begin by deciding whether the object is one crystal, a mineral aggregate, a mixed rock, or possibly manufactured glass, resin, metal, or ceramic. Record provenance before cleaning or altering anything. On a dry existing surface, observe lustre, transparency, natural growth faces, repeated cleavage, fracture, inclusions, grain boundaries, coatings, and relationships with surrounding minerals. Add only safe evidence already available: relative Mohs hardness, streak, magnetic response, heft, and geologic context. Quartz is Mohs 7 with vitreous lustre and no cleavage; amethyst, smoky quartz, rose quartz, and citrine are colour varieties rather than separate mineral species. Feldspar is near Mohs 6 and commonly has two cleavage directions. Calcite is Mohs 3 with rhombohedral cleavage, fluorite is Mohs 4 with four cleavage directions, common mica is soft and splits into elastic sheets, and garnet is hard with no cleavage. Magnetism supports magnetite-bearing material but not a meteorite verdict; a red-brown streak supports hematite even when its surface colour or lustre varies. Colour alone is weak because one mineral can occur in many colours and unrelated materials can look alike. Do not taste, heat, burn, grind, drill, polish, acid-test, or disturb a fibrous, dusty, radioactive, contaminated, valuable, or potentially toxic unknown. GeoMiner's private browser shortlist accepts only bounded lustre, hardness, breakage, and special-clue groups and records no specimen name, colour, photo, location, measurements, price, or free text. Natural versus laboratory-grown origin, treatments, geographic origin, and value require independent qualified gemological examination or laboratory reporting; a report is not an appraisal.