Group of quartz crystals, with developed prisms and defined terminal faces, between transparent to translucent, and with reddish tones due to hematite. With interesting parallel growths. These specimens were collected in this A Coruña quarry that exploits quartz, one of the main mines in the world due to the quality and quantity of its reserves. The mine was discovered in 1968 by three Galicians who gave their name (from their surnames SEñarís, RAma and BALboa) to the concession and who found it while exploring these mountains in the Pico Sacro area in search of "seixo" (from the Galician: hard white rock) of good quality.