Green Opal Post EarringsGreen Opal Post Earrings. Opal has been known as "The Gem of Love", and is thought to aid in psychic vision. The Opal is also believed to strengthen the memory. With beautifully varied colors, the Opal draws the eye to its brilliant shimmer. Each Green Lab Opal Post Earring is 5mm. These are Beautiful Green Lab Opal Earrings!