Exhibit Antiques has dated this piece to the 1750s.
Double Series opaque twist stem consisting of a pair of spiral tapes outside a 12-ply spiral band. Conical foot with a snapped pontil.

Jacobite sympathy example.
Date & Origin
England, c1760. Period of George III.
Condition
Excellent, age-related wear as shown.
Dimensions
Height: 15cm Bowl Diameter: 4.7cm Foot Diameter: 6.2cm.
Historical Relevance
Hand-blown around the time that the English clockmaker, John Harrison, produced the first successful marine chronometer “The No. 1 sea watch”.
Exhibit Antiques has dated this piece to the 1750s.
Specialists in 18th & 19th century antique glass
You can view the stock and full dealer information on the Exhibit Antiques Profile Page