What does covellite mean?
Covellite is a rare copper sulfide mineral with the chemical formula CuS, distinguished by its vivid indigo-blue to lead-grey colour, metallic lustre, and a tendency to develop an iridescent purple or blue tarnish on exposed surfaces. It typically occurs as thin tabular hexagonal crystals or as massive, foliated aggregates, and is found in only a handful of notable localities, including Mount Vesuvius in Italy — where it was first described — and significant deposits in Montana, United States. Because of its rarity and striking appearance, covellite is sought after primarily by mineral collectors rather than mined extensively as an ore, although it can accompany richer copper deposits. The name honours the Italian chemist Niccolò Covelli, who studied the mineral in the nineteenth century. In usage, the word belongs firmly to the vocabulary of mineralogy, geology, and collecting, appearing in specimen catalogues, scientific descriptions, and lapidary contexts, and it carries connotations of rarity, depth of colour, and scientific precision rather than everyday familiarity.
nounA rare indigo-blue copper sulfide mineral (CuS) that crystallizes in the hexagonal system, occurring as tabular crystals or massive aggregates and often showing an iridescent purple or blue tarnish.
- The rare copper sulfide mineral CuS, characterized by its deep indigo-blue color, metallic lustre, perfect basal cleavage, and iridescent tarnish, found notably at Vesuvius, Italy, and in Montana, USA.
"The specimen of covellite from Montana displayed a striking iridescent sheen under the museum lights."
"Thin plates of covellite glittered along the quartz vein, their surfaces shifting between blue and violet."
"Collectors prize covellite for its intense colour, which few other minerals can match."
Rarely pluralized except when referring to multiple distinct specimens or occurrences; in general geological writing covellite is treated as a mass noun.
"The drawer contained several covellites from different localities across the American West."
Named after a 19th-century Italian chemist who first studied it at Mount Vesuvius, covellite is the mineral that turns ordinary copper ore into sheets of metallic sapphire.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of covellite
Covellite takes its name from the Italian chemist Niccolò Covelli (1790–1868), who first investigated the mineral found at Mount Vesuvius, and the name was formalized in the mid-nineteenth century. The suffix '-ite' follows the standard mineralogical convention of deriving mineral names from the surname of the discoverer or early researcher. A closely related variant spelling, 'covelline', appears in older literature but is now largely superseded.
How covellite is actually used
A technical term used almost exclusively in mineralogy, geology, and among mineral collectors; it is rarely encountered outside specialist literature and is always treated as a mass noun or count noun for individual specimens.
Easily confused with covellite
Chalcocite is a different copper sulfide mineral (Cu2S), typically grey-black and softer in hue, whereas covellite is the deep blue CuS species.
Bornite, often sold as 'peacock ore', is a copper iron sulfide with multicolored tarnish, while covellite is specifically the blue-purple copper sulfide CuS.