Cassiterite is one of many underrated crystals that few use or even know about. It can be used for personal protection as well as grounding and protection against negative energies. It's a great stone that will ground and protect you against negative energies. This is why it is an underrated stone: It will help DEFLECT negative energies meant for you, back onto the sender. Most protective stones/crystals will block negativity but not necessarily send it back. So Cassiterite is extremely useful if someone or something keeps trying to harm you. Giving them/it a taste of their own medicine will encourage them to cease and desist. Cassiterite will also help channel your Divine Light into your physical body.