Provenite

Graubünden

RegionUnknownDraft data

46.7500° N, 9.5000° E · Region only

Smoky quartz from Graubünden, Switzerland, with photos of specimens from this locality.

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Minerals found here

Smoky quartz

Smoky quartz at Graubünden

Alpine cleft smoky quartz including twisted gwindel forms; the canton includes the famous gwindel locality Val Giuv

Twisted smoky quartz crystal (gwindel) with a serrated edge (specimen from Graubünden, Switzerland).
Twisted smoky quartz crystal (gwindel) with a serrated edge (specimen from Graubünden, Switzerland).
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Large gemmy smoky quartz crystals from the Swiss Alps, labelled Graubünden.
Large gemmy smoky quartz crystals from the Swiss Alps, labelled Graubünden.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Cabinet-size cluster of gemmy smoky quartz, labelled Graubünden.
Cabinet-size cluster of gemmy smoky quartz, labelled Graubünden.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Cluster of sharp transparent smoky quartz crystals, labelled Graubünden.
Cluster of sharp transparent smoky quartz crystals, labelled Graubünden.
Photo: Robert M. Lavinsky · CC BY-SA 3.0 · Source
Formula
SiO₂
Morphology
Twisted gwindel crystal with a serrated edge, gemmy
Typical size
Photographed miniature about 5 x 4 x 3 cm
Color / luster
Smoky, transparent
Twins
Gwindel (twisted growth)

Sources: SRC-168 SRC-134 SRC-169

About Smoky quartz →

Geology of the locality

Setting
Canton lying entirely in the Alps; Alpine cleft smoky quartz forms in extensional fissures in the central granite massifs (Aar and Gotthard) at about 450-550 C.
Host rock
Granite of the central Alpine massifs (regional)
Region
Graubünden
Country
Switzerland

The photo page gives only Graubünden and no more specific place, so the canton is used as the locality. Coordinates are the canton point from Wikipedia, not a collecting site.

Sources: SRC-168 SRC-134 SRC-169 SRC-170

Sources

  1. SRC-168 · Website
    File:Quartz-61040.jpg (Wikimedia Commons; smoky quartz gwindel, Graubunden)Robert M. Lavinsky · 2010 · Wikimedia Commons
  2. SRC-134 · Article
    Quartz crystals from alpine fissures: their formation and the historical significance of alpine quartz as raw material for objets d'artHuegi, M.F. · 2023 · 37th International Geological Congress (IGC), Tokyo
  3. SRC-169 · Database
    Val Giuv, Tujetsch, Surselva Region, Grisons, SwitzerlandMindat.org contributors · Mindat.org
  4. SRC-170 · Website
    GrisonsWikipedia contributors · Wikipedia

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.