Dilational vein may be syntectonic or unrelated to tectonic actvity but only to dilation through uplift. All nontectonic veins contain free growth of minerals from solutions. The growth direction is normal to vein walls but not under the influence of tectonic forces but because the hydraustic stress conditions in any system demand that the least principal stress must act normal to vein walls and this is the one of the easiest growth.