Localized in Pradena del Rincon, in the East part of the Sierra de Madrid. You can find these pegmatites along the road M-137, past the bridge on the Cochinillas river, and along the road M-127 (km 32). All at the South-West of the village.

The pegmatites intrude the metamorphic series (micashists, gneisses, leucogneisses).

Never exploited. The best emergences are along the road, cut by it.

1 to 10 centimeters crystals. Quartz, feldspar, muscovite, tourmaline (schorl variety), garnet. Terminated tourmaline crystals are quite frequent (1 to 5 centimeters long crystals are frequent) as well as 1 cm garnets.