“All that glitters is not gold”

My informant first heard this proverb when he was in elementary school. He grew up in New Mexico. His mother said it to him when he wanted to spend all of his allowance money on a toy he had seen an advertisement for. The proverb means that just because something seems nice or valuable on first glance, doesn’t mean that it actually is valuable.  I agree with my informant on the meaning of the proverb. I have heard it several times before, as it is a very common proverb in America. However I was slightly curious as to what it might be referring to.

Some possible origins for this proverb or meta-folklore about it is that when one is looking for gold everything in the sand is shiny and glittery. While you may get excited seeing something shining in the dirt, it often times is not gold, but pyrite or fool’s gold.  Miners were often fooled into getting excited over pyrite when it later turned out to be nothing of any value to them.