This simple mark seems to be the symbol 'Boku' 卜. It's an undocumented mark.
This measures about 2 1/2 inches in diameter.
Undocumented Mark, Boku, 卜, 2 1/2 Inch
Written by Keith Glein
Additional Info
- Maker's Mark: Undocumented Mark
- Shape: Glass Ball
- Color: Blue-Green
- Size: 2 Inch
- Rarity: Uncommon Maker's Mark
- Country of Origin: Japan
- ID (optional): 2021-08-02-01 Glass Float Museum
- Retail Value ($): 55
- eBay Auction ($): 45