https://www.d20srd.org/srd/spells/stoneskin.htm

Level:Drd 5, Earth 6, Sor/Wiz 4, Strength 6
Components:V, S, M
Casting Time:1 standard action
Range:Touch
Target:Creature touched
Duration:10 min./level or until discharged
Saving Throw:Will negates (harmless)
Spell Resistance:Yes (harmless)

The warded creature gains resistance to blows, cuts, stabs, and slashes. The subject gains damage reduction 10/adamantine. (It ignores the first 10 points of damage each time it takes damage from a weapon, though an adamantine weapon bypasses the reduction.) Once the spell has prevented a total of 10 points of damage per caster level (maximum 150 points), it is discharged.

Material Component

Granite and 250 gp worth of diamond dust sprinkled on the target’s skin.