Here's why:
* Geodes are cavities in rocks: They are hollow spaces lined with crystals.
* The minerals within the geode determine its characteristics: The luster, streak, and hardness you're asking about depend entirely on the specific minerals that have crystallized inside the geode.
Think of it like this: Imagine a geode as a treasure chest. You can't describe the treasure chest itself as having a specific luster, streak, or hardness. You need to open it and examine the treasures inside!
To understand the properties you're interested in, you need to know the specific minerals within the geode. For example:
* A geode filled with quartz crystals: Will have a vitreous (glassy) luster, a white streak, and a hardness of 7 on the Mohs scale.
* A geode lined with amethyst: Will have a vitreous luster, a white streak, and a hardness of 7 on the Mohs scale.
* A geode with calcite crystals: Will have a vitreous to pearly luster, a white streak, and a hardness of 3 on the Mohs scale.
Therefore, there is no single answer to your question. The luster, streak, and hardness of a geode depend entirely on the minerals it contains.
