A geode is a natural crystal or rock that resemble a round shape. They contain cavities within the rough outer shell and similar to a cluster they hold lots of tightly packed and often small crystals within.
When crystal geodes are opened they release the magic within for all to see. Because they come as a pair geodes are often gifted as a singular halve. Significant to those that maybe apart reminding them of each other as two halves make one.