This beautiful marble captures underwater life in glass and the size is about 2.75 inches. I created murrine to represent barnacles surrounding each other on a base of blue and green colored glass. This wonder is then embodied by clear glass that is shaped into a perfect sphere with a graphite mold.
You can watch a video of a similar marble being made:
https://youtu.be/I8fcyZnDzRw?si=RAvfsfpzfDY6FIzW