Group of crystals, one of them clearly dominant, which shows a very marked "window" growths (also called "skeletal") in the rhombohedron faces. In the prism, underdeveloped, we can see echeloned to parallel growths. Excellent glassy luster. With inclusions those are very common in this type of quartz crystals. These specimens were collected near the Urrúnaga reservoir in Legutio. Nowadays it is near impossible find these specimens.