Opal Rough- 18.2 g - (4)

Rough opal refers to uncut, unpolished pieces of opal that reveal the stone's natural form with flashes of play-of-color—a phenomenon unique to precious opals where iridescent colors shift with light and angle. Opal forms from silica-rich solutions in sedimentary rocks, creating a hydrated amorphous form of silica gel that hardens over time. Rough specimens are valued for their potential to yield cut gemstones, as well as by collectors who appreciate their organic and natural character. The raw texture and color spectacles provide insight into the geological conditions under which opals develop, particularly in renowned regions such as Australia and Ethiopia.