diamond ring turns brass

[Dark_Fury]

Happy New Year, everyone!

In "Hush, Little Baby" (a lullaby), there's a line "And if that diamond ring turns brass, Mama's gonna buy you a looking glass." Could you please explain to me the "diamond ring turns brass" bit, please? Does it say that the ring changes its color? What part of it becomes brass in color then? Why is it bad?

 

[Rover_KE]

'If an expensive item of jewellery suddenly loses its value ...'

Figuratively: 'If something that's precious to you loses its importance ...'

 

[Tdol]

It could mean that it's not real gold- just brass with gold leaf, which would wear off and expose the metal underneath. It's bad if you pay gold prices and get brass.

 

[GoesStation]

It's rather a mixed metaphor. Unscrupulous jewelers have sometimes represented brass rings as gold ones. The listener hears diamond ring as something like "expensive gold ring," so the line works.

 

[GoesStation]