This beautiful piece of art glass was likely produced locally here in Washington State. It is a shape that I have seen referred to as a bubble bowl by some glass artists. It is a hollow bowl. with an inner wall and an outer wall. If you imagine someone blowing a sphere, and then depressing the top into the concave shape of a bowl then you'd imagine the shape of this piece.
This piece is a wonderful mint green and pale blue in colour and hand blown. The base has a broken pontil which is open so you can see the inside of the bowl.
The bowl measures 3 1/2" in height and 4 1/2" in diameter. In excellent condition it has no chips, nicks or cracks at all. It does not appear to be marked or signed.