drused

Drused is a mineralogical term used to describe a rock or mineral surface that is coated with a dense layer of tiny crystals, known as a druse. This texture forms when crystals precipitate within cavities or along fractures, producing a glittering crust on the specimen. Drused surfaces commonly occur on minerals such as quartz and calcite, including quartz geodes and vug fillings, and may cover exposed surfaces or interior cavities.

The term can function as an adjective (a drused quartz nodule) and as a participle verb (to druse a specimen). In practice, drused textures are valued by collectors for their sparkle and contrast with the surrounding matrix.

Etymology: The term is derived from the mineralogical term druse, itself from French and related European roots, referring to a coating of small crystals on a rock surface.

See also: druse, drusy, crystal habit, geode.