Opals are formed from a solution of silicon dioxide and water. Water picks up silica from sandstone and transports this silica-rich solution to cracks and voids in rocks or fossils. Unlike other gems, opal originates from the deposition of silica in specific locations12. These gems are formed from sediments of silica and water that break down and form a gelatinous mass that hardens over time3.
xpuigc











