in theory you could make with a copper hammer, but odds are very low, like 1/1000 sorta odds
it's anything from copper-golden
most likely it's golden runic
trying to craft 3 exact properties with a copper hammer in probability is:
3/28 x 2/27 x 1/26 = 6/19656
= 1/3276 (1 in 3276)
bearing in mind that copper hammer would only have half it's crafts as 3 properties, we give 20 3 prop crafts per hammer, meaning in theory, it would take 163.8 copper hammers to be sure of crafting it with a copper hammer.
or ~80 bronze hammers.
with gold hammer odds go down significantly
golden hammer:
(3/28 + 3/27) x 2/26 x 1/25
anyone care to work it out? i cant be arsed working out what a fraction will convert 28ths and 27ths to be addable :S
84/756 + 81/756 = 165/756 = 55/252
55/252 x 2/26 x 1/25 = 110/163800 = 1/1489.1 (about 1 in 1500)
so all in all, you have about twice the chance to craft it with crafting 4 mod items, than you do with crafting 3 mod items