Can you get that by using a ruby? It doesn’t look like it’s on the list of possible obsidian affixes. Or do I need to Jasper a wizard legendary item that naturally has the affix?
Yep ! . You can get it by using ruby xtal .
Ruby : any red affix 
One of the posts I remember reading for 1.6 said something about “affix pools”, so I wasn’t certain if there were limitations to the affixes that you could get through ruby, obsidian, etc.