These are not plastic, these are not glass, these are not acrylic, they are "Lab Created" gemstones. The process is nearly identical to what you would find in nature. Look up Synthetic Lab Grown Diamonds or Sapphire and see how much they cost...There isn't a whole lot of difference in price because they are not "Fake" gemstones but merely lab created to imitate what is found in nature. The same is true with lab created Opals and there are dozens of them out there that I bet most people don't even know they are wearing or purchased. The price will be similar to what you would pay for a grade AAA opal anywhere else but lab created opals are stronger, more durable and have way more opalescent matrix than most natural opals. I am tired of people coming on here calling them "Fake". These are people who clearly don't know much about gemstones in general. Please, educate yourself before buying if you don't know much about created or lab created gemstones and what they are really worth if made of good quality like these are.Because I have ordered many different types of lab grown opals before and NOTHING out there has the same fire and flash as the Kyoto brand which has been around for decades. I have purchased other opals manufactured from other countries that don't even come close in quality. Gilson was probably the best LC opal but they don't make them anymore that I know of or Kyoto took over the Gilson name.And so, for those who are giving these a "Bad" rap because they are lab created, clearly don't know all that is involved in the process of making these. From what I learned reading up on the Company, they are made from the exact same chemical components as natural opal with the exception of water content. They take over a year to "Grow" into usable slabs of lapidary material and they are much tougher and less prone to chipping due to the lack of water content. These are not cheap to manufacture and I highly recommend those who don't know much about the process of lab created opals but dissed them for the price look up how they are made and why they are so expensive. Nothing shimmers quite like them though and everyone who has seen all the pieces I have made with these glare in awe and immediately want to know where to get them. Don't let the "Synthetic" part fool you. These are not being described right, they are lab created yes, but very valuable.