Is Costco diamond good quality?

Hello there, I'm curious about something. I've heard about Costco diamonds and I'm wondering, are they of good quality? When it comes to diamonds, quality is obviously a big factor and I want to make sure I'm getting a good deal if I choose to purchase one from Costco. Could you provide some insight into their quality standards and perhaps even compare them to other diamond retailers in the market? I'd really appreciate it!