I need to identify the figure of speech in this saying:"thy mind is an opal." I think it is a metaphor. Am I correct?

3 answers

Yes - that's a metaphor. Good!
I need to identify the figure of speech in this saying "good mistress accost, I desire better acquaintance" I think it's a pun am I right?
Good mistress is an example of a malapropism not a pun