I went on a tour of Boston years ago and was intrigued by some of the panes of glass in the windows of homes on Beacon Hill. Apparently, during the Civil War glass makers were forced to find a substitute for the lead used in glass making. They substituted manganese-ironically as a way to keep the glass nice and clear. Once exposed to ultraviolet light (like the rays of the sun) glass with manganese turns purple. Oops.
The most I've ever paid for a bottle or jar is $12.00, some I've gotten for as little as $2 or $3...I love the hunt, I love the bargain, but most of all I love seeing sunlight flood through the glass, showing off the soft purple colors...
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