Very nice Quartz or Black Obsidian Crystal pendant that has corresponding chakra gems. Both balance the chakras.
Clear Quartz is often called the "Stone of Power" and can help to amplify any energy or intention. Clear Quartz is also known as the "Master Healer", with its very high vibration, and is the most versatile healing stone among the crystals. Clear Quartz is said to protect against negativity, attune to your higher self, and relieve pain.
Black Obsidian is a grounding stone that provides an instant connection from the Root Chakra deep into the core of the Earth. Black Obsidian will help to clean and remove negative energies in a sacred space or environment. It also assists in releasing those emotions/reactions that cause negative energy such as anger, jealousy, greed, resentment, etc. Once these energies are removed/released, Black Obsidian will help to keep the space protected.