Normal could also be very close to low as could be very close to high.
Assuming that normal is around 30% and high is around 50%, with 12 fails in a row you could be in the "very close to low chances" which still normal but poor results.
My post was basically a "WTF, I failed 12 times in a row on normal!" post. That was posted 2 months ago and I wanted to share with the world my misery, but I've gotten over it now. I really don't know what the actual supposed percentage range is and it doesn't look like they will be giving this type of info out either.
The Refining article has been updated!
Legendary Jewelry Refining Stones have been distributed to everyone. If you want to claim it on an alt character, you must log out and claim it on the alt character, they are not tradeable.
For full details, please read the article HERE
Scroll down to the bottom of the page and also, note the red italicized text.