Quake is a magic spell in Final Fantasy VII Rebirth. It is granted by either 
Petrify Materia or Poison and Petrify Materia. It is the lowest level petrifying spell below 
Quakera and Quaga. Quake still inflicts a decent amount of non-elemental damage, as well as inflicting the 
Petrify status to one enemy.
Use[]
Quake can be cast when either petrify or poison and petrify materia is equipped. The spell deals strong non-elemental damage on its own, albeit with a relatively high MP cost compared to its peers. The petrify status is very dangerous to a foe, as it causes an enemy to turn to stone if they receive enough damage during the status.
Quake being non-elemental means it is a good way of inflicting damage against enemies that resist elements but not magic damage itself. Conversely, against enemies with an elemental weakness, it is both more efficient and more effective to cast the spell of the element they are weak to.
Quake can be amplified by some 
Support Materia. Both HP Absorption Materia and MP Absorption Materia can increase a party member's sustainability when using the spell. Magic Focus Materia can increase the spell's damage, and Magnify Materia can make for a powerful combination when it hits all enemies at once.
When paired with Synergy Materia, the caster can safely use the spell against any opponent as Quake spells deal non-elemental damage. Auto-Cast Materia is also an effective pair.
Using Quake with Aerith's Arcane Ward will cast it twice. Further using Yuffie with Doppelganger when in Arcane Ward can cast Quake four times, potentially overwhelming enemies.