One of the scandals post 2008 crash was how bankers in Switzerland would use diamonds packed into tubes of toothpaste to spirit millions of dollars out of various countries.
Diamonds were essentially a shadow banking system, with analogies to the way crypto exchanges work today. You put cash in to get a tiny portable stone that you could exchange for cash or deposits anywhere else in the world, and you could reliably transfer massive amounts of capital around without records. Simultaneously diamonds made wealth both highly visible, and completely invisible when they disappeared. No public ledger either.
Diamonds were essentially a shadow banking system, with analogies to the way crypto exchanges work today. You put cash in to get a tiny portable stone that you could exchange for cash or deposits anywhere else in the world, and you could reliably transfer massive amounts of capital around without records. Simultaneously diamonds made wealth both highly visible, and completely invisible when they disappeared. No public ledger either.