Log InRegister
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat Articles
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsThe ElementsUsersBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Cerro Granadas (Volcán Granadas), Rinconada Department, Jujuy, Argentina

This page is currently not sponsored. Click here to sponsor this page.
 
 
Volcano off.
Elevation: 4,184 m. asl.
It has identified the presence of sapphires in alluvial deposits in the vicinity of the Granadas Hill, West of the Sierra de la Rinconada, in the Northwest corner of the Republic Argentina. The place is accessed by route that connects Abra Pampa with Mina Pirquitas. Detailed exploration of the deposits have not been performed even though the sampling sites have shown that the found concentration exceeding 10 grams per cubic meter. Taking into account the extension of the volcanic activity responsible for the transport of sapphires to the surface, estimated that it is has all the conditions favourable to the discovery of economically viable deposits of gem-quality sapphires in the Puna. Stockings the sector coordinates are 22° 30´ of South latitude and 66 ° 30´de West longitude.

History of the discovery:
The discovery of sapphires in alluvial sediments of the Puna Jujeña was carried out in 1991 on the occasion of the exploration of alluvial gold. The first determinations by x-ray diffractometry X O. Morello performed them (CNEA: National Atomic Energy Commission) and its existence was reported by Zappettini and Segal (1994). Other subsequent findings were communicated by Sheridan and Gay (1995). The studies carried out on the material collected were synthesized by Zappettini et al.(1997).

Regional Geology:
The geology of the region is composed of a sedimentary Ordovician basement that hosts a gold vein mineralization and on which rests a sequence tertiary volcanosedimentary in turn covered by a group of andesitic-dacitic lava with interbedded ignimbritics, dacitic and rhyolitic domes are associated to it. The erosion of the previous units resulted in the formation of significant alluvial deposits.

Morphology of deposits:
Recognized manifestations are alluvial type. Sapphire crystals occur in sediments consisting of quartz, litoclasts of sediments and volcanic rocks. As accessory minerals there, as well as corundum, Garnet, gold, hercynite, magnetite, hematitezed pyrite, monazite and zircon. By its density, the sapphires are concentrated in heavy mineral-rich levels and often accompany the gold llampo(finely broken ore).

Mineralogy:
Crystals of corundum and sapphires occur in sediments with little rounding and size between 0.5 mm and up to 1 cm. Observed colors vary from colorless to blue. Crystals are frequent with zoning according to the c-axis, with alternating bands of different colours, just as there are sections in which the distribution of colors is irregular. There are less common varieties of pink. From a cristalografic point of view the most frequent forms are the rhombohedral, dominant in smaller crystals. Other types correspond to the prism of the first order associated with the pinacoid, with the typical form of Coop. In the crystals more elongated prism of the first order is associated with the pyramid. Forms of growth formed by the Association of basal faces and the rhombohedron are common. The study of the surface of the crystals identified textures of high temperature corrosion and the formation of edges of reaction consisting of hercynite magnesiferous. There are also textures produced by mechanical abrasion.
Carbonated and aqueous fluid inclusions and needle-like rutile, magnetite-rich inclusions in to the and it, pyrochlore, albite, likely columbite and mica Epigenetics. Determined by scanning electron microscopy and EDAX. Individuals with varying degrees of transport. Also added in the form of rosettes.

Mineral List



18 entries listed. 12 valid minerals.

The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

César, D., Viñas, N.A. y Lira, R., 1993. Museo de Mineralogía y Geología Dr. Stelzner. Universidad Nacional de Córdoba. Inédito.

Zappettini, E.O. y. Segal, S., 1994. Metallogeny of gold in Sierra of Rinconada, province of Jujuy, Argentina. The 9th Symposium of International Association on the Genesis of Ore Deposits, Beijing, China. Abstract, 1: 420-421.

Zappettini, E.O., Mutti, D. y Bernhardt, H.J., 1997. Génesis de zafiro y hercinita de la Puna Argentina. 8° Congreso Geológico Chileno, 2: 1598-1602.

Zappettini, E. O. (1999). Zafiros aluvionales de la Puna, Jujuy. Recursos minerales de la República Argentina. Instituto de Geología y Recursos Minerales. SEGEMAR, Anales 35: 1847-1849, Buenos Airs, Argentina.

Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2019, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: February 18, 2019 00:09:40 Page generated: January 19, 2015 09:10:56
Go to top of page