Antique Purple Sunglass Vase-Pre 1915. Excellent Antique condition Pre-1915.
Some wear to bottom of base due to age and use. Frilly Edge with scalloped
details. Large and heavy 3lb 8oz. Measures 9 inches tall with a 8 inch diameter
lip and 3 inch base.
An interesting characteristic of colorless glasses which contain manganese
dioxide as a decolorized is their tendency to turn different shades of purple
when exposed to the rays of the sun or to other ultra violet sources. This
changes the manganese compound into a form that causes the glass to turn
purple. During the mid and later 1800's virtually all American glass companies
were using manganese in their glass formula. Around 1915 the use of manganese
was discontinued and selenium became the chemical of choice as a clarifying &