@article{fdi:010079476,
  title = {{R}uby deposits : a review and geological classification},
  author = {{G}iuliani, {G}aston and {G}roat, {L}. {A}. and {F}allick, {A}. {E}. and {P}ignatelli, {I}. and {P}ardieu, {V}.},
  editor = {},
  language = {{ENG}},
  abstract = {{C}orundum is not uncommon on {E}arth but the gem varieties of ruby and sapphire are relatively rare. {G}em corundum deposits are classified as primary and secondary deposits. {P}rimary deposits contain corundum either in the rocks where it crystallized or as xenocrysts and xenoliths carried by magmas to the {E}arth's surface. {C}lassification systems for corundum deposits are based on different mineralogical and geological features. {A}n up-to-date classification scheme for ruby deposits is described in the present paper. {R}uby forms in mafic or felsic geological environments, or in metamorphosed carbonate platforms but it is always associated with rocks depleted in silica and enriched in alumina. {T}wo major geological environments are favorable for the presence of ruby: (1) amphibolite to medium pressure granulite facies metamorphic belts and (2) alkaline basaltic volcanism in continental rifting environments. {P}rimary ruby deposits formed from the {A}rchean (2.71 {G}a) in {G}reenland to the {P}liocene (5 {M}a) in {N}epal. {S}econdary ruby deposits have formed at various times from the erosion of metamorphic belts (since the {P}recambrian) and alkali basalts (from the {C}enozoic to the {Q}uaternary). {P}rimary ruby deposits are subdivided into two types based on their geological environment of formation: ({T}ype {I}) magmatic-related and ({T}ype {II}) metamorphic-related. {T}ype {I} is characterized by two sub-types, specifically {T}ype {IA} where xenocrysts or xenoliths of gem ruby of metamorphic (sometimes magmatic) origin are hosted by alkali basalts ({M}adagascar and others), and {T}ype {IB} corresponding to xenocrysts of ruby in kimberlite ({D}emocratic {R}epublic of {C}ongo). {T}ype {II} also has two sub-types; metamorphic deposits sensu stricto ({T}ype {IIA}) that formed in amphibolite to granulite facies environments, and metamorphic-metasomatic deposits ({T}ype {IIB}) formed via high fluid-rock interaction and metasomatism. {S}econdary ruby deposits, i.e., placers are termed sedimentary-related ({T}ype {III}). {T}hese placers are hosted in sedimentary rocks (soil, rudite, arenite, and silt) that formed via erosion, gravity effect, mechanical transport, and sedimentation along slopes or basins related to neotectonic motions and deformation.},
  keywords = {ruby deposits ; classification ; typology ; magmatism ; metamorphism ; sedimentary ; metasomatism ; fluids ; stable and radiogenic isotopes ; genetic models ; exploration},
  booktitle = {},
  journal = {{M}inerals},
  volume = {10},
  numero = {7},
  pages = {art. 597 [83 p.]},
  year = {2020},
  DOI = {10.3390/min10070597},
  URL = {https://www.documentation.ird.fr/hor/fdi:010079476},
}