Geode

Geodes are a rare consumable dropped by Granite-themed enemies with a 5% chance. Geodes can be thrown with the button, causing them to drop 2 types of gems on impact with blocks. The amount of gems varies from 3 to 6.

Tips

 * On average, the resulting contents of the geode are worth approximately 30 times more than its sell price.
 * This profit can be further increased by converting the contents to Stained Glass, which is worth about 10 times more than the gem ingredients and only requiring the addition of 10 Sand Blocks per gem.
 * However, Diamonds cannot be turned into Stained Glass, and as such, are most profitable being sold directly.

Trivia
Based on the design of the sprite, and the tendency for the geodes to drop gems when they break, it's likely that these are a reference to Stardew Valley, as they resemble geodes in that game, and have a similar behavior.