Earthquake

Earthquakes are a naturally occuring game mechanic that only occur in Caves. They occur semi-regularly. Earthquakes cause Rocks, Flint, Gold Nuggets, Nitre and Red and Blue Gems to fall from the roof of the Cave. This means those objects are now renewable. Earthquakes are dangerous, as the falling objects can hurt the player.

Effects
The camera will begin to shake, before the character says something along the lines of 'That didn't sound good'. Shadows will then form on the ground, being cast by falling material. If any of the items fall directly on the player, it will take damage.

Trivia

 * This is the first 'natural disaster' themed mechanic.
 * This has made all the items listed above renewable, besides Gold. Gold Nuggets were already renewable.
 * Gems are now much more readily available.
 * The Earthuake only occurs in the general area where the player stands. This makes it seem like Maxwellesque trickery.