This seems an odd choice as Onyx can be taken to signify indecision and so would appear an unreliable guide. On the other hand onyx can be used to release negative emotions and end unhappy or bothersome relationships. This makes more sense as anyone who saw Britney break down on TV can testify. ‘Strong Britney, strong Britney,’ she said tapping her chest furiously as she burst into tears. Let’s hope onyx means whatever Britney wants it to mean and not cast doubt on the power of placebo.