Gwindel Quartz Crystals

Gwindel Quartz Crystals From Tiefengletscher, Furka, Kanton Uri, Switzerland Credit: Anton Watzl

Gwindel quartz is a rare twisted or rotated quartz crystal habit, typically smoky in color. Instead of growing as a single straight prism, the crystal exhibits a subtle helical or spiral rotation of the crystal lattice along its c-axis, giving it a slightly twisted, “leaning” appearance. Individual growth steps can produce overlapping, stair-like crystal faces.

The term gwindel comes from the German gewunden, meaning “twisted,”. Many gwindels are smoky quartz, enhancing their visual impact.

Formation

Gwindel quartz forms in alpine-type fissures within metamorphic rocks such as gneiss and schist. These open cavities develop under high-pressure, low-temperature conditions during mountain-building events. As the crystal grows in a confined space subject to slow tectonic deformation, asymmetric stress causes the crystal lattice to rotate incrementally during growth. This slow, stress-controlled growth produces the distinctive helical or “corkscrew” structure. Unlike faden quartz, which records repeated fracturing and healing, gwindel formation reflects steady rotational growth rather than breakage.

Key Characteristics

• Twisted Habit: Prism faces are not parallel; the crystal shows a visible helical or spiral rotation.
• Platy Structure: Many specimens grow sideways, roughly parallel to the a-axis, resulting in slightly flattened, tabular crystals.
• Macromosaic Surface: Crystal faces often consist of interlocking sub-crystals that create a mosaic-like texture.
• Occasional Scepter Forms: Some gwindels develop a larger, twisted termination perched on a narrower base.

Occurrences

Classic localities include the Swiss Alps (Grimsel, Gotthard, Mont Blanc, Val Giuv), the French and Austrian Alps, and alpine-type fissures in Pakistan’s northern ranges. These crystals are highly prized by collectors for their rarity, aesthetic form, and the insight they provide into slow crystal growth under tectonic stress.