Shiny things are very important. They can reflect the shininess from photon emitting sources. They can also reflect shininess from other shiny things. To prove that the importance of shiny things is not just superficial, I am going to explain the origins of some common idiomatic expressions that came from shiny things...

Acid Test
The most common usage for this term today is the reference to browsers complying with standards, as tested by a series of HTML, CSS, and JavaScript. Though, a casual reference to something "passing the acid test" may still be used to refer to it being genuine.

The acid test originates from ancient times when a chemist or smith would wish to determine whether or not a sample substance was gold or not. Gold was the first known "noble" metal (though many others have been discovered more recently), which could withstand individual acids, specifically hydrochloric and nitric. Yet, when theose two acids were mixed in a 3:1 ratio, they could dissolved gold. This substance became known as "aqua regia" (royal water) because of its ability to dissolve the noble metal. By taking a small scraping of gold and placing a drop of the acid on it, purity could be determined when watching for the speed of the fading as the gold dissolved.

...Pans Out
This expression usually ends a sentence, such as "I hope this all pans out." It refers to the hope of success in a situation.

Gold prospectors learned quickly that the sediments in riverbeds could be gold-rich, so they invented ways to extract that gold. Since gold is fairly inert and very dense, it would often exist in relatively-pure nugget form beneath the surface of the other sediments. This required scooping with a pan to get to the gold. The prospectors would them slosh around the contents of the shallow pan in hopes of separating out the valuable gold from the worthless sand and dirt.

Born with a Silver Spoon
Since silver is a relatively rare metal, owning full sets of silverware was a sign of wealth. The term referred to a baby being born into a wealthy family.

Sterling
The term refers to something of high quality or as the name of the British currency, Pounds Sterling.

Sterling originated as a term from an old French silver coin. It evolved over the centuries as being the best alloy of silver, containing 92.5% of the metal and 7.5% of another metal (usually copper). Any more silver would cause faster tarnishing and easier denting; and less silver would lose the properties that would make the piece desirable. The British Pound originally was valued at one Troy pound of sterling silver, which would be 373g or 0.8Lbs.

Pay through the Nose
This expression refers to the requirement of one to pay more than desired.

The term originated from an ancient Danish house tax that resulted in a person being slit on the nose for failure to pay a piece of gold to the government.

Slag
A slag is a loose woman or man.

The term originates from the smelting process of gold that would leave a worthless layer or iron and other metals behind, known as the slag layer.


Bonus: Argentina
The country's name came from Latin "argentum", which means "silver". Although there were no major deposits of silver discovered by early explorers, they were led to believe that the area was rich in it.