Vintage ball vase, mouth-blown, layered glass

The base of this vase is opaline glass, overlaid with brown/red glass and then decorated in the centre with black glass threads. The bottom clearly shows by the tear that this vase was mouth-blown. A very well crafted piece of glass art.
Condition: excellent, no chipping etc., only some signs of wear on the bottom.
Dimensions: height 20 cm, width 19 cm, depth 17 cm