hand lens

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hand lens A hand-held, steel- or plastic-mounted, optical magnifying system usually consisting of two or more optical elements, which is used in the field to provide an enlarged image of rocks, minerals, and fossils, ranging from 5X to 20X. Hand lenses vary in diameter from 0.5 to 1.5 cm, can be carried conveniently in a pocket, and form an essential tool in a geologist's field kit.