Can anyone identify this vase and it's maker?

[thepearlyqueen]

I found this vase at an auction along with a batch of McCoy and Roseville. Its beautifully made, glazed  identically inside and out. There's a small circle mark incised right at the base which I haven't been able to identify. Does anyone recognize it? The mark is about 3/8 inch in diameter. The vase stands about 7 inches tall with a max diameter is around 5 inches.

Thank you in  advance to anyone who can help.

[mountaingigi]

It's nice ... but probably incidental that it was among McCoys and Rosevilles, as it looks like a studio pottery piece to my eyes.