Tumblestone - Obsidian, Mahogany A single tumblestone measuring approximately 15mm - 25mm in size. £1.00 Quantity: at £1.00 each Add To Basket 0 in your basket View Basket Checkout A grounding and protective stone that gives strength in times of need. Eliminates energy blockages and stimulates growth on all levels. It can stabilise and strengthen a weak aura. Can relieves pain and improve circulation.