While listening to the classic "Diamonds are a Girls Best Friend" song in the store I came to the realization that they haven't always been the go-to rock or tradition!
The tradition of engagement rings dates back to the Classical era, and for the first few hundred years of the tradition, only the wealthiest nobles could afford precious stones. Most rings were actually just simple metal bands! The tradition of the ring finger came from the belief that there was a vein running straight from what is now known as the left "ring finger" to the heart.
When a larger portion of the population became able to afford rings with precious stones (not just diamonds) engagement rings became highly symbolic. Sets of stones would have personal meanings. A ring style commonly made used the birth stones of the engaged as well as their parents to create a ring. The Victorian tradition of engagement rings included precious stones such as Lapis Lazuli, Opal, Vermarine, and Emerald which spells Love! Some engagement rings during this era also contained compartments for a lock of the betrothed's hair (ahh really?).The tradition of diamond solitaires actually all began with a campaign by De Beers in the 1940's!
Some other food for thought is that diamonds can actually be a boys best friend too... it is still traditional is some places for the man to wear an engagement ring too!