10mm round cabochons Australian mined. Australian mined Boulder Opal is Opal in an ironstone matrix. Opals have long been used by aborigines for ceremonial 'dreamtime'! Boulder Opal inspires the bond between the earth & stars. It generates strong grounding properties and cleanses the aura. Develops healing state by strengthening communication between conscious & sub-conscious minds. Supports mental clarity, emotional protection, physical wellbeing & spiritual development. Strengthens eyesight, assists recovery from Parkinson's & provides comfort during childbirth. Sample photo.