McCoy opalescent vase

This McCoy vase is 9 1/4" high x 5 3/4" wide. I inherited a few pieces of McCoy pottery from my grandmother who died in 1958 through my mother who died in 2001. It is all standard McCoy sort of matte colors and fairly thick. I didn't know McCoy made snazzy stuff like this. I only found one other, similar but smaller piece using a google search. Thrift shop find for $2.99 plus tax today. Interesting piece and an eye opener for me. In perfect shape. I am curious to know the years that this style of vase was made. '50s? '60s?