I'm probably going to start political parties on the antique bottles page due to this question. Lol.

[Jimmy Langford]

OKAY GUYS. Today I'm going to ask the question that I hear many people say different answers on. WHEN (circa) did manganese glass stop generally being made. I hear 1915, 1918, and even 1920s. Of course small bottling plants may have kept using manganese but I'm talking about the majority of plants.

 

[Harry Pristis]

 

[Csa]

Great explanation. Thank you.

 

[ROBBYBOBBY64]

So the amethyst coloration is due to oxidation of the manganese? I never thought about why. I just knew it happened. Harry that is the most thorough reply I've seen yet. They all know UV light is the culprit but never explained indepth. Thanks again Harry!
ROBBYBOBBY64.

 

[Robby Raccoon]

In general, most collectors say it ended at the start of WW1, but recycled glass cullet and stockpiles of manganese would surely have kept it going till 1918 or 1919 in many areas.

 

[CanadianBottles]

I've got a manganese jar with a date of 1915 on the base, but I've never seen any conclusively dated to after the war so I imagine the switch-over happened gradually as stockpiles were used up.

Unfortunately this article is hidden behind a paywall, but the first page they let you view is interesting in that it clears up what I think is a common misconception about manganese https://pubs.acs.org/doi/pdf/10.1021/ie50369a016. It wasn't Germany itself that was supplying all the manganese (the country doesn't seem to have any manganese deposits at all) but rather that the war was making it significantly more difficult to get manganese to North America from Russia or India, so what they were able to get would be diverted into the war effort instead of glass factories.

 

[ROBBYBOBBY64]

I've got a manganese jar with a date of 1915 on the base, but I've never seen any conclusively dated to after the war so I imagine the switch-over happened gradually as stockpiles were used up.

Unfortunately this article is hidden behind a paywall, but the first page they let you view is interesting in that it clears up what I think is a common misconception about manganese https://pubs.acs.org/doi/pdf/10.1021/ie50369a016. It wasn't Germany itself that was supplying all the manganese (the country doesn't seem to have any manganese deposits at all) but rather that the war was making it significantly more difficult to get manganese to North America from Russia or India, so what they were able to get would be diverted into the war effort instead of glass factories.

That makes sense. Also the USA not joining the war until 1917 still provided war materials to Russia and the other allies. Thanks for the link.
ROBBYBOBBY64.

 

[Bottle 2 Rocks]

Here are some late 20's soda bottles that were all manufactured by J.T. and A Hamilton glass works out of Pittsburgh bearing their mark (H inside triangle) they used from 1900 to 1943 . Two are 1928 dates and the Papy bottle is 1929, (shown is a patent date of 1928 for that particular design). The last 2 clear ones are also 1929 and carry the very slightest of pink tint. A later Papy bottle I have in clear bearing no maker marks apparently made at a different glass house may show that they switched , being unhappy with the product Hamilton put out that was laced with manganese. Later bottles by Hamilton showed they finally got their act together. It doesn't hurt my feelings any because I think they look great in the window.

 

[Bottle 2 Rocks]

Here is something else to wrap around this possibly. Heat may be a factor as well as seen in these rhodochrosite (manganese carbonate) mineral samples that got there color without exposure to sunlight. Pulled right out the dark depths displaying rich color. These examples were formed with hydrothermal heat in most cases. In some cases this rhodochrosite mineral was used as an ore of manganese. There are other minerals that are colored pink by manganese but I'll stop here.

 

[ROBBYBOBBY64]

Here are some late 20's soda bottles that were all manufactured by J.T. and A Hamilton glass works out of Pittsburgh bearing their mark (H inside triangle) they used from 1900 to 1943 . Two are 1928 dates and the Papy bottle is 1929, (shown is a patent date of 1928 for that particular design). The last 2 clear ones are also 1929 and carry the very slightest of pink tint. A later Papy bottle I have in clear bearing no maker marks apparently made at a different glass house may show that they switched , being unhappy with the product Hamilton put out that was laced with manganese. Later bottles by Hamilton showed they finally got their act together. It doesn't hurt my feelings any because I think they look great in the window.

Thats a crazy twist looking papy bottle. So I guess they were still making bottles into the 1920's that used manganese as a clarifier. Whether from recycled glass or not. Still this proves at least to me. That there are always exceptions to the rule.
ROBBYBOBBY64.