Seeing an opal in a dream refers to your libido and sexual desire. The dream indicates that you need to be more passionate in your life and in love.

…The significance of stones (precious and other-wise). Amethyst, success in courtship; blood-stones, legacies; coral, a birth; cornelian, treachery; diamonds, drowning; emeralds, great success in the arts; jasper, inconstancy; opal, separation, divorce, rapture in friendships; pearls, great sorrow; rubies, lover’s kisses; turquoise, the breaking off of an engagement; sapphires, a wedding; common pebbles, petty troubles; black rocks, illness and death; sand, a serious calamity; chalk, ailment or death of a child; granite, accident on land; marble, death.To dream of teeth coming out portends illness or death, but not necessarily of the dreamer. For example, a man told me that, on the night preceding the death of one of his brothers, he dreamed his teeth fell out, and that on one of them was a portrait of the brother who died….