Hematite
Hematite is the most powerful gemstone to use for grounding. It can help you clear away confusion and orient you toward practical action in the real world. It brings the energy of higher consciousness down through the chakras to your root, and helps you transform that energy into physical reality.
Hematite bracelets are handy to have on hand when you are working with higher-chakra gemstones, to keep you grounded.