There are several crystals that are commonly used for shadow work. Here are a few examples:
 
1. Obsidian: Known as the "stone of truth," obsidian helps to reveal deep-rooted emotions, fears, and negative patterns, making it an excellent crystal for shadow work.
 
2. Labradorite: Labradorite is a powerful crystal that aids in uncovering hidden aspects of oneself. It assists in self-reflection, releasing old patterns, and embracing one's true self.
 
3. Smoky Quartz: This grounding stone helps to transmute negative energy and emotions, making it useful in shadow work. It assists in facing and accepting parts of ourselves that we may have previously avoided.
 
4. Amethyst: Amethyst is a calming and protective crystal that enhances self-awareness and introspection. It can assist in accessing and understanding hidden emotions or experiences during shadow work.
 
5. Black Tourmaline: Considered a powerful protector, black tourmaline helps to create a safe space for shadow work. It aids in grounding, releasing negative energies, and fostering emotional healing.
 
Remember, the choice of crystal ultimately depends on your personal intuition and connection to the stones. Explore and choose the ones that resonate with you the most.