Floating druse of quartz crystals forming pineapple growths, with a good luster and a slightly yellowish hue. On the backside, also crystallized, we can see the typical kaolinite layer of this deposit. It is accompanied by a limonite that was probably pyrite.
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.