# Only OLD glass turns purple???



## bobclay

Hello all, 

 Many misinformed people think that only pre 1914 glass will turn purple. This is simply not true. It IS true that the supply of manganese (which causes the purple color when exposed to UV or radiation) was shut off because of WWI, but that does not mean that ALL purple or SCA glass predates 1914.

 Here is an example of a 1970s vintage jar that has turned purple, probably by using a purpling box at some time, judging by the shade of purple it is.

 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6265602909

 I know this is a 70's vintage (1977 to be more precise) jar because I emailed the seller and asked him to tell me the letter and number in the thread area which identifies where and when this jar was produced. I think it is very unusual to see a modern jar that has turned purple, but proves that glass does not HAVE to be old to do so. 

 Bob Clay


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## IRISH

That is pretty late for one,  anything with Manganese Ozide in it will go though to some degree regardless of age.
 I've seen a few 1930's even 40's Crown seals and machine made internal threads turn a pale purple in sunlight,  a friend has a 1930's milk glass jar that's gone too, purple milk glass is an odd looking thing [] .


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## bobclay

Hi Irish,

 About the only reason I can think of as to why this glass batch may have contained some manganese is from the cullet source. I worked for Ball and I know we had to buy our cullet from many different sources and each batch of raw materials had to be mixed with a certain percentage of cullet (broken glass) in order to melt properly in the continuous flow furnace. If possible, we avoided using window glass as cullet because it was too brittle and they had to alter the other raw materials to compensate for that for making containers. I know we (Okmulgee, OK Ball plant) used Selenium at this time (mid 1970's) as a decolorizer in our batches of raw materials purged into the furnace.

 One of the early Kerr plants was located at Sand Springs, OK about 40 miles from where I live. They used sand from the Arkansas River in their glass and sometimes in many of their earlier jars in the teens and twenties, the colors ranged to a smokey gray color. It remained in operation as a Kerr facility until the mid 1990's when Ball bought them out. They closed that Kerr plant and merged it with the Okmulgee, facility. For a couple of years, we made Kerr fruit jars at the Ball plant!

 I'd say this particular jar we are talking about is very unusual in this color, whether it was naturally SCA or purple boxed. Unusual? Yes. Commanding a big premium? Up to the individual. For all we know, there are MANY of these clear jars that would turn purple like this one has. Even a small batch of glass in today's furnaces is 350 tons, and that makes a LOT of jars! 

 Always something else we learn each day about our interesting hobby.  )

 Bob


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## capsoda

I had a light fixture on my front porch the the glass turned purple in. Was made in China in the 1990s. 

 Ivan got that one.


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## bottleboy311

I have seen European botlles for the 30's and 40's turn purple. Paticularly perfume bottles from France. Also a lot of Austrailian bottles post WWI have turned purple. As far as your Chineese porch light fixture glass turning purple Warren, it just wanted to fit in with all you bottles and jars.

 Lee


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