kind of diamond: What No One Is Talking About
http://devinmsem465.angelfire.com/index.blog/1685067/dont-buy-into-these-trends-about-blue-sapphire-rings-vintage/
The heat that results in the diamond may even exceed 1,two hundred degrees Celsius. Everything less than four hundred levels Celsius results in graphite, not diamond. Mention heat. It corresponds to the warmth,