Antique bottle order 1890's light purple from sunlight

This wonderful old bottle is light purple from sunlight. It is marked with a patten DATE of April 1895 and has the number 4 in the center of the base. It was blown into the two part mold and has bubbles in the glass. The lip was hand tooled.
The bottle measures 5 inches tall and is 1.75 inches order across the base.
There is a place that looks like a magic marker mark but when I turn the bottle it disappears. My thought is that it must be a closed crack that has minerals in the crack. Next to it on the inside is a raised place shaped like a tiny fish hook.
This is an interesting find. Love the delicate purple color!