Hi all,
That website is fascinating.
I am guessing (but have not contacted anyone at the site) that this person has access to some great dumping areas from the 1880- 1940 period... I see lots of medicinal bottles from the very early 1900s. Also pieces of pattern glass.......daisy and button and others. And/or maybe the artist has had the opportunity to buy damaged glassware of various colors and patterns, and used such items to create shards? Very interesting.
Btw, looking closely at the "purple milkglass" window, I see several white (and purple) milkglass inserts for canning jars, the type used inside zinc lids for the typical "BALL" mason style canning jars..... They are the perfectly round pieces of glass. Most of those types of inserts were made of opaque or translucent white milkglass (and I have seen an occasional example with an opalescent greenish or bluish tint) ; they were produced in massive numbers by Hazel-Atlas and other companies. Most of them probably date from the 1880 to 1940 period (H-A after 1902).
Another thought.....all glass contains cullet (broken, recycled glass) and I am sure in many cases a glass factory could not always have been sure what ingredients were in a particular batch of cullet that they were adding the molten glass mixture. Does anyone have an idea what colors of glass cullet was "allowable" in making new white milkglass? Perhaps this would be why some manganese was included in the recipe......not only could there be trace amounts of manganese from the cullet itself, but more could have been added to the batch to counteract any unwanted colors in cullet.
Of course, all of this still doesn't cancel out the fact that some small quantities of as-made lavender / purple milkglass date from the Victorian age, and more recently as well.
David