BNWT Fifth Ave Collection Necklace with blue gemstone

Fifth Avenue Collection - “One of a Kind” necklace. I’m trying to find out what stone this is, sky blue with an opalescence. 3 Cubic zirconia set in a trilogy at the top of the pendant setting. Chain (stainless steel) is 16in long, plus 3 inches with extender long. Style of chain - rope chain or wheat chain Never worn (only for pictures)