First and foremost: zircons are the oldest gemstones on the planet with samples found that are billions of years old!
Secondly: CZs are imitation dimonds
Other Bling stones: diamond, Moisannite, spinel and garnet
Diamonds, spinel and garnet are single refractive - zircons are double refrative (more on this later).
Thanks to De Beers (the diamond cartel) diamonds have been touted as THE most coveted gemstones. The fact is diamonds are quite common - so much so that De Beers actually will only allow a fraction of the diamond sources to be mined. The don't have to worry, when one mine plays out there are many others to open. The only exceptions are champagne, pink, mocha and chocolate diamonds. De Beers lost out on these because when they were discovered in Austrialia they were kept under wraps until they could the protect these stones thus muscling out De Beers.
About 13 or 14 years ago champane and pink diamonds exploded on the scene! Eventually, LeVian trade marked their LeVian Chocolate Diamonds.
The Aussies were't worried - they still controlled champagne and pink diamonds, which in my opinion, were much more beautiful! If you have the time, take a look at champagne diomonds on JTV (Jewelry Television), the stones not the ones set jewelry. I still remember the first time I saw one 12 years ago, it took my breath away! If I'd had the $$$ I would have bought as many as I could. I did manage to buy a champagne pendent (cluster style). They were so new friends and coworkers would hug my neck for a closer look. Sadly, the mine is playing out, another souce has yet to be found and prices have greatly increased.
Now back to zircons and how refraction comes into play. Refraction is the play of light INSIDE the stone as it passes from air into a denser substance such as crystals, reflection is the bounce of light off the surface. This is what gives gemstones their sparkle. Don't worry, I need more time to research refraction (in layman's terms) and will expand on in Part 2
Dispertion is the rainbow of light seen when you shine a bright light from above over a dark surface. Diamonds (on a scale of 1 to 4) have a dispertion of one. Moissanite a 2, strontium titnate a whopping 4. Moissanite - discovered by the French geologist Moissan in the meteor crater in Arizona - is now mostly (or entirely) lab created. It's silicon carbanate as opposed to diamonds which are crystalized carbon. The gemsone, strontium titinate, has a whopping dipersive index of 4 and is found in nature and created in a lab. Interestingly both Moissanite and strontium titinate were both made in a lab before being found in nature!
Black diamonds versus black spinel: spinel is sooo much more sparkly than tux black diamonds. The reason? Spinel has a smooth surface while black diamonds have pits on the surface - invisable to the naked eye - which drasticly reduces it's reflectivity. This is why the prices of spinel have been steadly increasing.
Part 2 - zircons and garnets to come...