Vintage Finnish hand-blown glass birds with smooth and lava crackle finish

So special! I found this pair of hand-blown art glass birds when we were on a trip to Jyvaskyla, Finland, this summer. They have a very interesting finish. Part of each bird is smooth, and the other part has a lava-like crackle finish that almost looks like stone. Very cool, I’ve not seen anything like it before. They are approximately 3 x 5” and 2.5 x 3.5”. Pretty shades of black, with silver, gray and clear.