Some Gemstones are more sensitive than others...
If you're a proud owned of Opal stone, you should remember to take particular care of this piece. Opals are stunning but delicate & porous stones, thus they are sensitive to heat & liquids, but giving a wash from time to time with some soap water & then drying it (so not letting it be soaked) is fine. Also, don’t expose your opal to extreme conditions of light, heat, or dryness.
Coral is a soft gem & to keep it beautiful, you should keep it safe from your other jewelry (to avoid scratches). It is also a porous gem, so to protect it, don’t wear your coral piece in pools & don’t expose it to heat or chemicals (including any cosmetics) - you would risk losing its shine & color.