The Cabaços vein of quartz is the biggest and most prominent sample of veins of this kind existing in the Freita mountain. For example, it is possible to observe it from the Frecha da Mizarela viewpoint, as well as from the Castanheira village. This happens because of its milky-white tone, as well as its high resistance to weathering/erosion in relation to the fitting metasediments. This aspect associated to its big dimension makes it prominent in the territory and allows its easy cartography. As we come closer to this geosite, we become aware of the real dimension of this body, whose dimensions are superior to 8 meters wide x 12 meters length and 2 meters high.
This monomineralic mass presents a NW-SE orientation, like the most of the veins we find here. The establishment of these veins is related to the circulation phases of residual magmatic fluids, eventually in the final phases of the granite crystallization of Freita mountain and the nodular granite of Castanheira.