If your absolute favorite stone is the Opal, you're out of luck…literally since this stone is said to bring bad luck to whoever wears it. This superstition stemmed from the best selling novel 'Anne of Geierstein' by Sir Walter Scott in 1829 where Lady Hermione was falsely accused of being a demon as she dies shortly after a drop of holy water accidentally falls on her opal jewelry and changes its color. This book had such an effect on the image of the Opal that shortly after its publication, the Opal market crashed and Opal prices dropped by 50%.