Here is a source for super cheap lab created gems which the below book states are better than natural gems on the grounds of the relative purity of their crystalline structure/chemical composition:
https://www.jamminggems.com/lab-created-gemstones.aspx
book: "19 big secrets about astro gems" by Heinz Krug and Dr.Thurston:
https://www.scribd.com/document/329973424/Secrets-about-Gems-eBook-V1-9-pdf
https://www.jamminggems.com/lab-created-gemstones.aspx
book: "19 big secrets about astro gems" by Heinz Krug and Dr.Thurston:
https://www.scribd.com/document/329973424/Secrets-about-Gems-eBook-V1-9-pdf