All that Glitters is not Gold

Britain has done remarkably well in the Paralympic Games, coming second with a current tally of 64 golds. Second place is usually a disappointment, but we've punched above our weight, considering the greater population of China, which comes first. 

Interestingly, gold medals at Olympic and Paralympic games are not in fact made of gold, but gold-plated silver. This has been the case since 1912. The silver medals are genuine enough, as are the bronze. The reason for going cheap on the golds is of course money. A genuine gold medal would cost around £19,000 to make, compared with the current cost of around £490. 
This reminds me of the phrase 'not all that glitters is gold', a corruption of Shakespeare:
O hell! what have we here?
A carrion Death, within whose empty eye
There is a written scroll! I'll read the writing.
All that glistens is not gold;
Often have you heard that told:
Many a man his life hath sold
But my outside to behold:
Gilded tombs do worms enfold.
Had you been as wise as bold,
Young in limbs, in judgment old,
Your answer had not been inscroll'd:
Fare you well; your suit is cold.
-The Merchant of Venice, 1596. 
Surprisingly, there's no reference to fake gold in scripture (I'd be interested to hear from anyone proving me wrong). One theme that is found in scripture, however, is that there are some things much better and valuable than (genuine) gold:
How much better to get wisdom than gold! To get understanding is to be chosen rather than silver. -Proverbs 16:16
Gold is a truly beautiful substance. Little wonder it has been so highly prized by so many for so long. But Shakespeare warns us that just because something sparkles, it may not be precious. Scripture warns us that even the genuine article need not be precious enough.