Exhibit Antiques has dated this piece to the Before 1700 period.
An indented Roman glass vessel in a rare miniature square form.
Sloping shoulders lead to a square body with indented walls. The base kick is slightly conical with a pontil scar.

Date & Origin
Roman, Mid to Late Imperial Empire 2nd - 4th century CE.
Condition
Intact, small encrusted burst air bubble and further minor pitting with flaking encrustations and iridescence throughout.
Dimensions

Height: 3cm Diameter: 2.8cm
View documented examples in chronological order here:
2nd - 3rd century CE: https://www.metmuseum.org/art/collection/search/239654
2nd - 3rd century CE: https://www.metmuseum.org/art/collection/search/244693?deptids=13&ao=on&ft=Glass&offset=1080&rpp=40&pos=1090

3rd - 4th century CE: https://www.cmog.org/artwork/jar-34?search=collection%3A2f3eede750a0f2456fffd7f02a011de2&page=183
3rd - 4th century CE: https://www.cmog.org/artwork/jar-47?search=collection%3A2f3eede750a0f2456fffd7f02a011de2&page=222
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