Stone Skin

Stone Skin is an active skill that can be taught to Sorcerers at level 60. It cannot be ranked up.

Stone Skin can be performed with a disc by the Sorcerer to quickly get out of sticky situations in PvE, especially if a boss is focusing on you. This skill drops aggro if boss is chasing you and makes you invulnerable 1). Generally it has too long cooldown to actually use it to dodge special attacks.

1) Actually you can still take damage while in stone statue form. It's been noticed that you lose HP on attack that would one-shot you. Possibly the skill is implemented as shield that absorbs high damage, least twice your total health. Also one-shot wipe mechanics will kill you.

Skill will continuously lower aggro after cast. If you cancel the skill by pressing the skill button again and continue attacking, you will continuously lose aggro and drop out of combat mode.

It is not as useful in PvP, if there's no one to come to your help within 5 seconds the skill lasts.

Rank table
To obtain, one must find a Magic Instructor and pay a certain price of gold dependent on rank.

Glyphs
To glyph, a glyph must be obtained and learned only once. At level 60, a character has 50 glyph points available to spend on all available sorcerer glyphs. Most glyphs, specifically common glyphs can be purchased from a Glyph Master, while fine glyphs must be looted from enemies.

(Disclaimer: As NPC shop prices vary depending on a variety of factors, the prices below are subject to variation. Only take them as benchmarks.)