It was listed by Exhibit Antiques. Sold pieces stay on Sellingantiques as a record of what has passed through, and the next one is rarely far away.
Exhibit Antiques has dated this piece to the Before 1700 period.
Beautiful flaking iridescence.
Spherical body with a flattened base and slightly concave bottom; a distinct tooled constriction between the body and cylindrical neck. Plain, knocked-off vertical rim.

Date & Origin
Roman. Late Imperial Era, 3rd - 4th century CE.
Condition
Layers of iridescent flaking encrustations with further iridescence to the weathered glass surface.
Dimensions
Height: 6.8cm Diameter: 5cm

View documented examples in chronological order here:
2nd - 4th century AD: https://ancientglass.wordpress.com/2012/05/30/roman-spherical-bottle/
3rd - 4th century AD: https://www.ktb.gov.tr/EN-120323/late-roman-imperial-period-glassware.html
4th century AD: https://www.metmuseum.org/art/collection/search/239644
Exhibit Antiques has dated this piece to the Before 1700 period.
Specialists in 18th & 19th century antique glass
You can view the stock and full dealer information on the Exhibit Antiques Profile Page