This authentic cobalt blue kugel glass Christmas ornament was made in Germany in the late 1800s. It's nearly 3-1/4 inches diameter with a circumference of just over 10 inches. I've shown a normal size coffee mug in the last photo for scale.
Kugels are colored within the glass, not painted or finished on the outside, and the mercury silvering is on the inside. The ornament has deep cobalt blue coloring, softened by slight deterioration of the inner mercury silvering, which can only be seen when you hold the ornament to strong light. The blue coloring is quite a bit darker than my pictures show.
The eight lobe embossed brass cap is firmly attached and does not slide. There are a few small bubbles in the glass, which is common. For being well over 100 years old, the kugel is in wonderful condition with no damage.