Silver and Class
As probably one of the oldest forms of mass produced money, it isn't surprising that silver has associations with class all over the world.
Silver coins have been found all the way back to around 600BC. Silver's rarity and malleability made it a good candidate for minting money - it had an almost 'inherent' and universal value and could be stamped fairly easily to mark it as a coin.
It is important to acknowledge here that forced labour and slavery used to mine silver is what boosted the colonial economies and brought to the surface huge amounts of silver under horrific conditions.
As such, it makes sense that if you could afford to have your silver sitting on a shelf in an aesthetic form for your own pleasure, rather than in your purse, that you were using silver as a status symbol.
Before it was commonplace for cutlery to be provided in place settings, it was customary to carry one's own spoon around, like you would a wallet or keys. A silver spoon specifically denoted class, giving a visual marker to others that you were a skilled craftsman or landowner.
To be born with a silver spoon in ones mouth is a phrase used to mean born into affluence. The phrase likely comes from an old tradition of giving a silver spoon as a gift to an infant at their christening. Supposedly it was usual for the affluent to give a set of 12 apostle spoons, each bearing the image of a different saint, and for godparents who could not afford 12, a single spoon, sometimes with a patron saint on, would be gifted instead.
The use of silver cutlery also gave birth to another euphemism for wealth - 'Blue Blooded'. Privileged families who ate from silver platters or using silver cutlery developed a medical condition called Argyria, which is a build up of silver in the bodies tissues, giving the skin a bluish appearance. In addition to this, rich families might avoid being out in the sun (and thus being associated with manual workers) which only served to enhance the odd, pale blue colouring of their skin.
Other origins of the term blue blooded are thought to relate to racism in medieval Spain, where showing one's wrist to show the blue veins beneath proved one as noble (in contrast to people with darker skin tones). Or possibly to 'The Royal Disease' of haemophilia, connected to a rare blood type which supposedly contained higher amounts of copper and made veins appear more blue under the skin. I personally favour the Argyria theory, as a silver wine goblet alone could leach 100s of parts per million of silver in the wine, though all three theories probably contributed to the continued usage of the phrase to refer to people of wealthy descent.