Dear Gioia,

Thank you for contacting Mearto with your appraisal inquiry.

The presented object appears to be a Roman-period flask or balsamorium with a height of 5.5 inches. Such small vessels were used for oils and were mainly produced in the Eastern Mediterranean Sea regions. This vessel was buried in the earth and came from an excavation. The iridesdent glasze is partly corroded.
Comparable objects were recently offered and sold on the international auction market. 
This piece is in medium condition and no severe damage is visible in the images provided.
A fair market estimation would be between 150 to 300 USD.
This estimate is based on actual recent past recorded auction sales of comparable items. Retail "asking prices" can be higher and may vary.

With kind regards,

George