I too have a dazzling faceted diamond on my engagement finger. I love it. It sparkles and sends little rainbows on the wall whenever the light is right. A diamond is made of a unique crystal formation that lends itself to scientifically proven cuts that bounce the light perfectly around the diamond's crystal structure and back out to the eye. The lapidary can master the physics of light-bounce in this gem, much like an expert billiards player. The diamond is also the hardest mineral on earth. This combination of light transmission and hardness lives up to the hype. The magic of a diamond is not overstated -- even if it's rarity is.
But not all gems are built like a diamond, and so they should not always be cut like one. And if you think so too, you're not alone. History agrees. Take a look at the rings of royalty throughout history, and you'll see masterfully polished, rounded colored gems. Saturated sapphires and aquamarines in magnificent golden settings were the norm for millennia. The mineral structures of a beryl (emerald, aquamarine, morganite) are completely different from those of a corundum (sapphire and ruby). Because of that, light will behave differently once it enters the gem. The cutter should take this into account. What has happened over time is that cuts from the diamond chart have been applied to the crystal structures of other gems and it almost seems like putting antlers on a bear.
There are a few lapidaries who facet specific to the gem species' own crystal structures and not according to the chart of diamond cuts. I'm quite grateful to know some of these master gem cutters and love each time I get to set one of their stones. There is NOTHING like a tourmaline faceted for a tourmaline's optimum brilliance. One example is Jean-Noel Soni of Top Notch Faceting. I have met him numerous times, and his cuts are like no other. The quality of his cutting makes an instant and lasting impression.
Sometimes, the saturation and "garden" inside the gem is so perfect, that the lapidary simply polishes a rounded form, called a cabochon. This yields luscious colors, and soothes the eye as the light seems to undulate almost like a cat's eye. For me, there is nothing like staring deeply into a soft curve of an tourmaline cabochon. And nothing represents regal to me more than a rich blue sapphire cabochon set in high karat yellow gold, as it evokes Parisian majesty and reminds me of walks at the Palace of Versailles. And though it isn't as trendy these days, I have a guilty pleasure for a roman red garnet ring. Garnets are my birthstone, and red is hard to resist.
The cabochon is a sensual approach to gem cutting and I love to work with them. But I'm not fanatical about this, and I do love my faceted color stones equally.