Also perception will determine if you see all the things you can mine or not, from what I read.
While I'm not aware of this being accurate, I don't know that's it's not.
What i >do< know is that perception determines your percentage for obtaining HQ items. Currently, the cap is 15% natively. Later on, some nodes give a +5% HQ chance if your perception skill is high enough. Furthermore, you have an ability (100GP) that grants and additional 10%, and one for 300GP that grants an additional 30%. Edited, Oct 31st 2013 1:23pm by LebargeX
It's false. Once you open the relevant page in your mining log (e.g. once you hit 21, you can see the 21-25 page in the log), you are able to access those nodes. When you first hit a node, everything will be "unknown," with a 25% success chance. Once you successfully hit an unknown node, you get the 1st time exp bonus + regular exp, and the item becomes viewable, along with it's "normal" gathering stats.
The only determination to what you can "see" is level (unless we are talking 50+ gathering - different story). If you are 25, you can only see up to & including level 25 nodes. Once you ding 26, you can now see level 30 nodes.
Also, you have an ability that shows you the minimum perception needed to potentially HQ an item
. This starts @ 1% if you just make the requirement, up to a native max of 15%, as Lebarge said. With node bonus + 300GP ability, you could have up to a 50% HQ chance on an individual node.