Golconda pegmatite
18.8508° S, 41.9489° W · Region only
Beryl and Elbaite from Minas Gerais, Brazil, with photos of specimens from this locality.
Minerals found here
Beryl at Golconda pegmatite
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
- Formula
- Be₃Al₂Si₆O₁₈
- Morphology
- Tabular hexagonal crystals dominated by the basal pinacoid
- Typical size
- About 1.5-9 cm across on the pictured specimens
- Color / luster
- Colourless (goshenite); transparent to translucent, glassy
- Associated minerals
- Muscovite
- Availability
- Scarce
- History
- Labelled as old-time finds
Sources: SRC-703
Elbaite at Golconda pegmatite
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
- Formula
- Na(Li₁.₅Al₁.₅)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH)
- Morphology
- Doubly terminated gemmy crystal
- Typical size
- Specimen about 4.2 cm
- Color / luster
- Green with fine luster
- Surface features
- Natural etching on one termination
Sources: SRC-263
Geology of the locality
- Setting
- Pegmatite near Governador Valadares (per specimen label).
- Region
- Minas Gerais
- Country
- Brazil
Coordinates not filled: no coordinate source could be opened in this session. Coordinates: Centre of the city of Governador Valadares (Wikipedia, 18°51'03"S 41°56'56"W), NOT the pegmatites. GIA article places Golconda I-III northwest of the city, with Golconda II about 33 km by road along the Coroaci road and the three mines within 5 km of each other (https://www.gia.edu/doc/Gem-Pegmatites-of-Minas-Gerais-Brazil-The-Tourmalines-of-the-Governador-Valadares-District.pdf). Mindat gives only a rounded estimate (18°S 42°W, about 9 km margin). Coordinates: Centre of the city of Governador Valadares (Wikipedia, 18°51'03"S 41°56'56"W), NOT the pegmatites. GIA article places Golconda I-III northwest of the city, with Golconda II about 33 km by road along the Coroaci road and the three mines within 5 km of each other (https://www.gia.edu/doc/Gem-Pegmatites-of-Minas-Gerais-Brazil-The-Tourmalines-of-the-Governador-Valadares-District.pdf). Mindat gives only a rounded estimate (18°S 42°W, about 9 km margin). Coordinates: Centre of the city of Governador Valadares (Wikipedia, 18°51'03"S 41°56'56"W), NOT the pegmatites. GIA article places Golconda I-III northwest of the city, with Golconda II about 33 km by road along the Coroaci road and the three mines within 5 km of each other (https://www.gia.edu/doc/Gem-Pegmatites-of-Minas-Gerais-Brazil-The-Tourmalines-of-the-Governador-Valadares-District.pdf). Mindat gives only a rounded estimate (18°S 42°W, about 9 km margin).
Sources
- SRC-263 · Website
File:Elbaite-157329.jpgRobert M. Lavinsky (photo); Wikimedia Commons · 2010 · Wikimedia Commons (via download.osmand.net mirror) - SRC-303 · Website
Governador Valadares, Minas Gerais - Wikipedia - SRC-703 · Website
File:Beryl-136232.jpgRobert M. Lavinsky · Wikimedia Commons
Draft data from the Provenite workbook. Check entries against the cited sources before relying on them. Photos are open-licence images from Wikimedia Commons; the author and licence are given with each photo.