If it is a capital R in the triangle, then this is the symbol of the Reed Glass Company of Rochester, NY. I find this entry in Toulouse's Bottle Makers and Their Marks.
Unfortunately the entry has no discussion of what they made so we are no closer to the use for this bottle / jar.
As for age, this is mid 20th century. Upon reflection, I guess it could be an ink bottle. The shape does not lend itself to food or medicine in my opinion.
It is intriguing and has some visual value...definitely more so than most plain clear bottles of this era but I don't think you will find a whole lot of collector interest. It probably has some small decorative value.
Chris