Green’s Dictionary of Slang

shiney, the n.

[glittering coins]

money; cite 1851 refers to fraudulent ‘gold’.

[Aus]Bell’s Life in Sydney 26 Apr. 3/4: [He] submitted the ‘shiny’ to a small chemical process.
[UK]C. Reade It Is Never Too Late to Mend 1 35: We’ll soon fill both pockets with the shiney in California.
[US]St Louis Globe-Democrat 19 Jan. n.p.: The young man [...] feels impelled to ask his friends if they have any ‘rocks’ or ‘shinies’ about them.