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Galena vs Graphite: Weight, Cleavage and Paper Mark

Galena and graphite can both look gray, metallic, soft, and capable of marking paper. Galena is extraordinarily heavy and breaks along three right-angle cleavage directions. Graphite feels light and greasy, splits in one direction, and leaves a black mark on paper or fingers much more readily. Compare equal-sized pieces in your hand. Galena feels dramatically heavier and commonly shows cubic cleavage. Graphite is light, greasy, sheet-like, and readily leaves a black mark. Handle suspected galena as a lead-bearing mineral and never grind it. Do not begin by scratching. First compare heft and look for three right-angle cleavage directions. Check texture with minimal handling. A greasy feel and black residue favour graphite. If needed, make a gentle paper mark with a clean edge. Graphite normally writes much more readily. Use streak and hardness only with controlled technique and immediately clean the work surface if galena is possible. Treat mixed metallic ore samples as uncertain if only a few grains are visible. Galena contains lead. Do not grind, lick, heat, wear, or give suspected galena to children; wash hands after handling and keep it away from food areas. Avoid creating or spreading dark mineral dust. Use disposable paper or a washable test surface and follow workplace hygiene requirements. High density supports galena but does not establish lead concentration or economic value.