Rough Blasting Powder in AH ?

Hey guys i just learn engineering skill today and i want to make the first item Rough Stone and to make RS you need Rough Blasting Powder. I read couple guide on internet they say i can buy this from AH, but when i type this item in AH i found nothing. Does it mean nobody sell this item or i do something wrong when searching ?

You can buy Rough Blasting Powder from vendors, if that's really what you need:
http://wotlk.cavernoftime.com/item=4357

But I think you got it backwards. You need Rough Stone to make Rough Blasting Powder. And you can buy Rough Stone on AH.