What you see in stores commonly called Moissanite is a lab created synthetic, and since it is manmade, cannot be considered rare. If really should be called Lab Moissanite or Synthetic Moissanite
Cultured Diamonds are "cultured" in a laboratory apparatus. Crystals grow, and a "cultured diamond" is grown in a chamber. These stones don't meet the criteria of rarity.
Lab Created diamonds are manufactured in ever larger quantities - beware.
Basically, it hides the cracks. "Good", you say. "Bad", sez I. It won't take nearly as much of a blow to fracture that diamond. If a jeweler ever has to re-tip the setting and doesn't know the diamond is fracture filled, that stuff bubbling out is what once filled those cracks.
Likewise, that diamond put in an ultrasonic cleaner could have some serious damage.
Pegasus™ is a process invented by General Electric™ that uses pressure and heat to "whiten" diamonds. Reputable labs such as GIA™ and EGL™ will divulge any "enhancements", assuming they have detected them - and they probably will.
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