Skarner Runes explained
There's one set of runes for Skarner on patch
11.7
that is the clear favorite for LoL players and pros alike. The best Skarner Runes on the position 
Jungle are Sorcery as the primary path and
Inspiration as the secondary path with a pick rate of 63%. Besides runes you should take a look on Skarner Build and if you are interested in pro matches take a look at Skarner Probuilds. If you want to discuss
Skarner then you should visit the champion subreddit.
Primary path on Skarner
Sorcery empoweres abilities of Skarner and increases the available champion resources. Most of high elo players – and our LoL pros in the the major regions – have agreed that
Phase Rush is the best keystone rune to run on
Skarner.
Phase Rush offers more flexibility and options to betake oneself in and out of danger, which can be helpful since that's essentially the main playstyle of Skarner. This is usually followed up by taking
Nimbus Cloak,
Celerity and
Waterwalking.
Nimbus Cloak, which grants movement speed upon using a summoner spell, works amazingly well with junglers in particular as they take the shortest cooldown summoner spell,
Celerity boosts all movement speed bonuses to Skarner.
Waterwalking grants movement speed in the river, which helps Skarner get around the map quicker. The extra damage will also help in those all important dragon and baron fights.
Secondary path on Skarner
When it comes to your secondary path, most
Skarner players prefer to go with
Inspiration.
Inspiration opens creative opportunities on Skarner troughout the match. On the
Inspiration path, the best runes for Skarner are
Cosmic Insight and
Hextech Flashtraption.
Cosmic Insight grants summoner spell and item haste. Having an extra way to decrease the distance with the
Hextech Flashtraption will make an engage much easier to pull off.