Antique Food Container Bottles and Purpling.

Old Food Bottles (3 Purpled)

These are old food container bottles found along the Treasure Coast.  This type of bottle seems to be more likely than others to turn purple.  That is said to be caused by manganese dioxide used in the glass before 1914, although that is not a perfect cut-off date and some bottles, including more recent example, were artificially purpled.

In my finds, it seems the most sun-purpled bottles are food container bottles.  Maybe pickle bottles.  I always wondered if the contents might have some effect on purpling, but I've seen no evidence of that in the literature.

I do have a couple pharmacy bottles that are nicely purpled, but other than that very little purpling among my finds.

The bottle on the right is the only one marked with a patent date - Aug. 20, 1901.  Of course, the patent date isn't the date of manufacture, which you'd expect to be somewhat later.

None of these are blown bottles.  On the bottle that has not purpled, the seam marks would suggest an older age than the other bottles.  The general impression would be that older bottles are more likely to be more purpled, but that doesn't seem to be the case here.

It seems you can't tell much about age from sun-purpling other than the general date of 1914 being generally accepted as general dividing line.

Below is another food container bottle, but that one has a maker's mark (J. K. & S), which dates it to around 1857 - 1900, older than the above bottles, and obviously a different type of glass (light green) that did not purple

The J K & S maker's mark is rare.  I showed an example in an individual post on that bottle in this blog.

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