Opal is the substitute stone for the planet Venus. Hence, you may strengthen the effects of Venus in your life by wearing Opal. Planet Venus brings prosperity, love and joy in life. Also, it makes you more beautiful. People under Taurus & Libra sign are highly influenced by Venus. Hence, Opal gemstone effects people under Taurus & Libra sign more positively. Opal is also taken as a substitute of diamond. Astrologically, Opal's effects are same as diamond. Also, Opal gemstone is quite cheaper than diamond. Hence, mostly people opt for Opal if they are recommended to go for diamond.