The dragonglass" fire and earth elemental properties boosted almost every aspect of the alloy and even facilitated the process of imbuing magic in the bronze. Enchantments also had a multiplicative power in magically powerful numbers of three, seven or thirteen. But he didn't know of any material that could bear thirteen enchantments at the same time and not fall apart from the strain. Bearing seven enchantments also seemed to be beyond the limits of most things too, including bronze, so he had to settle for three.