Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
tetragonalrareHalides
Cumengeite
Pb21Cu20Cl42(OH)40
This specimen features vibrant deep blue, often bipyramidal or tabular crystals, sometimes forming aggregates, on a matrix. The crystals exhibit a distinct adamantine luster.
Cumengeite Physical Properties
Mohs Hardness
2.5Crystal System
tetragonalLuster
adamantineStreak Color
pale blueCleavage
perfect on {001}Fracture
conchoidalSpecific Gravity
4.71Colors
deep blue, azure blue, indigo blueTransparency
transparent to translucentType Locality
Amelia Mine, Santa Rosalía (El Boleo), Boleo District, Municipio de Mulegé, Baja California Sur, MexicoMineral Group
HalidesUses
collector, mineralogical researchAssociated Minerals
boleite, pseudoboleite, atacamite, gypsum, cerussite, anglesite, calciteRarity
rareGeological Context
Cumengeite is a rare secondary mineral that forms in the oxidized zones of lead-copper ore deposits, typically in arid or semi-arid environments. It is a product of the alteration of primary sulfide minerals.
