Old bottle, bluish glass
No marks. Measures 5 1/8" tall x 1 11/16" wide x 11/16" front to back. All four sides are concave, with the (front?) deeper concave. Side seams extend up to middle of neck. Holds approx a little over 6 tsp of fluid up to the shoulders. Limited number of tiny air bubbles in the glass. If it looks like the neck is crooked, it is.
Any ideas as to age? Thank you.