Heart of Earth

You feel your flesh strengthen with the power of stone. This spell converts part of your body into elemental earth, which toughens you considerably. You gain a +8 bonus on checks to resist a bull rush, overrun, or trip attack. You also gain temporary hit points equal to twice your caster level (up to 30 hp). Furthermore, while this spell is active, you can activate a Stoneskin effect (as the spell) on yourself as a swift action. This benefit lasts for 1 round per level (or until the stoneskin's total protection is consumed), at the end of which time the spell's entire effect ends. If heart of earth is active on you at the same time as Heart of Air, Heart of Fire, or Heart of Water, you gain light fortification. If all four of these spells are active on you at the same time, you become immune to extra damage from critical hits and sneak attacks.
 

You toughen your flesh with the strength of stone, converting parts of your body into elemental earth. You gain 4d8 temporary hit points and gain resistance to bludgeoning, piercing, and slashing damage from nonsupernatural attacks for the duration. If you are affected by both this spell and either Heart of Air, Heart of Fire, or Heart of Water, critical hits scored against you instead become normal hits. Once all of the temporary hit points granted by this spell are gone, this spell ends.   At Higher Levels. When you cast this spell using a higher level spell slot, increase the amount of temporary hit points gained by 2d8 for each slot level above its base level.