Val Giuv (Tujetsch)
46.6922° N, 8.7014° E · ± 1 km
Smoky quartz from Graubünden, Switzerland, with photos of specimens from this locality.
Minerals found here
Smoky quartz at Val Giuv (Tujetsch)
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
- Formula
- SiO₂
- Morphology
- Single crystals, pairs and twisted gwindel crystals
- Typical size
- Photographed specimens 5 to 7 cm
- Color / luster
- Cognac-coloured to dark smoky, lighter in aplite pockets, water-clear and glassy
- Associated minerals
- Adularia and other feldsparscalcitechlorite
- Twins
- Gwindel (twisted) crystals are characteristic
- Availability
- Scarce
- History
- Searched for about 200 years, so most accessible clefts are exhausted; pockets often need drilling or blasting
Geology of the locality
- Setting
- Glacial valley in the south-eastern Aar massif; Alpine fissures are concentrated in the Giuv syenite, a weakly metamorphosed quartz-monzonite / quartz-syenite, and in aplite dikes.
- Host rock
- Giuv syenite (quartz-monzonite) and aplite dikes
- Region
- Graubünden
- Country
- Switzerland
Coordinates converted from 46 deg 41 min 32 s N, 8 deg 42 min 5 s E on the Mindat locality page. Collecting needs a permit from the Tujetsch community.
Sources
- SRC-169 · Database
Val Giuv, Tujetsch, Surselva Region, Grisons, SwitzerlandMindat.org contributors · Mindat.org - SRC-438 · Website
Collecting in Val Giuv, Alps, SwitzerlandSpirifer Minerals · Spirifer Minerals - SRC-447 · Website
File:Quartz-119121.jpg and related Giuv Valley files (Robert M. Lavinsky)Wikimedia Commons · 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.