Condition: Size: 8 * 8 cm/3.14 x 3.14 in (Length x Width ) Note: please pay attention to the size . the photo is for reference .it is a natural energy of rock, some rock have a little texture on the stone Features: Material: volcanic stone Color: Black These are naturally harvested, unpolished Basalt stones used for hot stone massage therapy. The Basalt stones used for bodywork were created by the long, slow cooling of molten lava spewed from volcanoes located in different regions of the world. These special Basalt stones are chosen for massage since they retain heat most any other kind of stone due to their high iron and magnesium content as well as their extraordinary density. Hot stone massage is a unique variant of massage therapy that employs heated stones to release physical tension and calm the nervous system. Package Included: 2 * Massage Stones Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.