Has anyone used Glamira?

Just looking to see if anyone has ever purchased from Glamira.com. They get great reviews. I am looking for a ring for my girlfriend (looking to spend around $800-$1000) and I am considering sapphire. I emailed and customer service to ask whether or not their sapphires were natural and if they were treated. They got back to me and said they ARE natural and they are NOT treated. Not even heat treated. They have 1 carat sapphire rings in 18k gold for under $1000. Is this possible?
See link:
Glamira Ring Alegra 1.0 crt