This is a Moissanite Tennis chain. This is the most comparable stone when it comes to comparing to a diamond. It shines brighter, lasts just as long and passes a diamond tester. Every single piece we sell will come with an official GRA certificate showing its authenticity and all of the specifications. These are VVS stones. Any questions or videos of proof needed in terms of authenticity please let me know I will be more than happy to provide. Shipping will usually take 3-7 business days. If the item must be made then shipping will be about 5-10 business days, we will let you know in advance if this is the case! Thank you!