It says so, but I'm not sure this is actually the case. Same as with Dwarven smiths which are said to excel at magic forging... but they don't unless they make their namesake Hammers! Probably they held such ability at one time... and Tartarian Cyclops, iirc, also has such mentioned in its description...
I would prefer them to be more costly in return to having consistency with description... or description changed.
