How does one identify true Ruby Glass made with gold vs a later version made with copper? How does one identify an original Johann Kunckel antique glass?  Kunckel was a 17th century German alchemist, apothecary and glassmaker whose items are now museum collectibles. The deep, intense color of the red was produced by the addition of gold to the glass, a method and recipe pioneered by Kunckel.  His Glass dates to around 1685, Kunckel’s first decade as glassmaker to the court of Frederick William I, Elector of Brandenburg.   Only about 20 of Kunckel’s early gold ruby red glass pieces are known to exist.  Is this number 21?

The above, is a beautiful antique glass that I believe to be red ruby antique glass, handmade with a rough pontil and a folded foot.  The glass has hints of gilding, most of which has been lost due to time and age.  I see no physical damage to the glass.  The glass looks like it might have been designed/constructed. in 4 parts with a twist balluster and five pointed decorative "leaf" type supports for the bowl.  I can see the circular spin marks in the bowl where the bowl was pushed out by the glass maker.