Tumbled stones have a smooth feel, are pleasant to hold and to wear and good to look at. You will find them in a wide variety of sizes. Owing to the portable nature of tumbled stones it is easy to carry a collection of them with you depending on the energies you want to work with on any particular occasion. Tumbled specimens of darker colored stones, such as Obsidian, Hematite and Black Tourmaline can be combined to provide grounding energy when you feel that your thoughts are scattered. They also bring a deep sense of security and safety by anchoring your energies down through your Base chakra and into the Earth, so this combination of tumbled stones would be an excellent choice for anyone going through periods of anxiety or emotional turbulence