Each stone is unique and can vary slightly in size, shape, color and drawing from the picture.
Obsidian is created when lava cools down quickly with a water content of no more than 4 percent. With higher contents of volatile substances (in addition to water mainly CO2), the rock would otherwise, even with rapid cooling, bloat to a pumice stone. Pechstein develops when it cools down slowly.
Note: The effect of gemstones, minerals and crystals has not yet been scientifically recognized. All statements on this page are not intended as a diagnosis or therapy.