EFG99AN6: Group of Quartz crystals (smoky variety), one of them clearly dominant and well centered on the matrix, doubly terminated, with parallel growths and very marked 'gwindel' twisting. The crystals are very transparent and lustrous, have an intense and deep smoky color, and are accompanied by small Albite crystals.
Greater perfection, transparency and color than other similar specimens.

Grimsel corresponds to a high-mountain alpine area located in the Hasli region, in the Bernese Oberland, mainly known for the Grimsel mountain pass and for its numerous alpine clefts where high-quality mineral specimens have been found. The Hasli region is a historical and geographical entity within Bern Canton.

From a geological point of view, the area belongs to the Aar Massif, dominated by metamorphic crystalline rocks such as granites, gneisses and schists. Alpine fissures developed in these rocks have produced associations of Quartz (often smoky variety and 'gwindel' forms), Albite and other minerals typical of low-pressure, moderate-temperature alpine hydrothermal environments.
Grimsel area, Hasli Valley, Bern  Switzerland (±1990)

Specimen size: 19 × 11.2 × 8.6 cm = 7.48” × 4.41” × 3.39”

Main crystal size: 9.7 × 6 cm = 3.82” × 2.36”