i did look at the stats and i have to say that this build is working fantastic :)
don't be so sceptic :P
as already mentionend i'm gonna post a vid, so u will see that my offensive runes r quite usefull

nono that'S a rune page especially for skarner

and i thought about an improved ghost, but as i was testing it, i thought it's not that good at all

but thanks for u constructive critic :D
and no flaming reply like OMG U SUCK UR BUILD IS TOTALLY ****, u know? :D
but plz first try my build out, and vote after that, PLZ :(

this rune build depends on good farming ability, so the "only 2 AD" r a little bit usefull ;)
as i said, u can swap them into macic resistence glyphs i that fits better to u ;)

and u also say they r good for jungling, so... what r we doing on a solo lane?
FARMING, right :)

and if u compare the runes and the 2 (!!!!) critical strike items, u get about 40% critical strike chance

I would have to say that your guide needs a lot more work. The build order is terrible and reveals that you really haven't looked at the stats close enough.
You rush atma's with the motivation "it gives u great tankyness for ur lane aswell as for the mid and late game", well... no, it doesn't.
It is an offensive, and rather expensive, upgrade to the chain vest providing no tankyness at all.
If you need that armor early then buy the chain vest, you can spend the 1655 gold it takes to upgrade it to atma's for the crits and the damage when you have enough health to make the passive cost effective and enough AD to make the crits worth it.

I don't like the runes at all.
0.28 AD glyphs? How is that attractive?
And crit chance? You have one skill that scales of that (poorly) and you get one in that at level 3 and then not again for 10 levels... why would you think that was especially good for your skarner?
Is this a rune page that you had for another champion?

Your masteries are fine on the defensive tree, I like that you get nimbleness, but I can't see how you could motivate not getting archaic knowledge and the CDR over what you have.
2 flat ArPen is nothing, 15% MPen when you have no flat MPen is huge. I don't think the attack speed could be said to be so much better than CDR to motivate this.
You should at least get improved ghost and not the 2 armpen.

Why do you suggest getting secondary attack damage runes? The damage increase from them is so minimal that the're pretty much only used for jungling, it also doesn't help that they are secondary. Secondly, why do you get critical strike runes when you have only one item in your finished build that gives critical strike chance? Wouldn't it make more sense to get an Infinity edge for the increased crit chance and damage, instead of the Hextech gunblade or Rylai's? This guide is obviously unfinished so im not voting on it, but you have a long way to go.