Volcanic Lava Stone
Volcanic Lava Stones are the sub-family of rocks that form from volcanic lava. They are called igneous volcanic rocks which are different from igneous rocks that form from magma below the surface (igneous plutonic rocks). When the lava of different volcanoes cool and harden they differ much in their appearance and composition. They all have an irregular porous surface.
You can rub a drop or two of any essential oil on lava stones/beads as a jewelry diffuser.