Humankind's fascination with precious stones long predates the establishment of gemology. The Romans believed that diamonds were splinters of falling stars, while the ancient Greeks considered them to be the tears of the gods.
Pearls were also highly prized in ancient societies. Regarded as a currency for affection and love, the silky round bulbs were often offered to women on their wedding days to promote fertility. Today, the value of a gem is more likely to be dictated by auction records than superstition. But while you can put a price on a precious stone, its value is determined by more than just supply and demand.
There may be evolutionary reasons why we gravitate towards shiny objects. Research published in the Journal of Consumer Psychology suggests that gems evoke the glossy surface of a body of water. Our pursuit of them may be rooted in a simple urge to survive.
In the study, researchers blindfolded participants and asked them to touch a picture of a landscape. They were then asked to guess how much water featured in the image. Those touching glossy surfaces guessed a higher proportion of water than those given matte paper.
The study's co-author, Dr. Vanessa Patrick, believes that the association between glossy surfaces and the images they conjure may offer evolutionary reasons for our love of shiny objects. "We wanted to rule out the 'pretty' explanation," said Patrick, who's also a professor of marketing and director of doctoral programs at the University of Houston.
Pearls have often been used to project power, according to Inezita Gay-Eckel, a jewelry historian and professor at L'École, a Paris-based school founded by the jewelry brand Van Cleef & Arpels.
Today, there are scientific ways of assessing the value of a precious stone. In addition to its rarity, a gem's market value is often determined by its clarity, cut, color and carat -- colloquially known as the "four Cs."
But ultimately, a jewel is worth whatever bidders are willing to pay for it. Just like in the art world, contemporary culture and trends also play their part.