Topic: Yellow/green color in gold ruby cased in clear lead glass

[cagney]

A vase and water pitcher most likely American from the last quarter 19th century. Under a strong light and the right angle a curious other color becomes apparent. I am pretty sure these are gold ruby cased in clear lead glass. lead glass confirmed by short wave UV light.

[cagney]

Water pitcher photos.
  I am wondering if this is only a curious effect in gold ruby cased in clear. Do not have an un-cased example of gold ruby to try and replicate this effect.

[Fuhrman Glass]

In some conversations with Dudley Giberson a well recognized studio glass artist and researcher , his contention was that back when these were made that pure gold was not available and that there was always small amounts of silver in the gold and this was why the gold ruby would show up as some others colors under different lighting. I remember him getting into a heated debate with David Whitehouse of the Corning Museum over this conjecture. Dudley made many different formulations and melts over his 50+ years of working glass.

[cagney]

I did surmise that might be the case. Possibly the clear lead glass accelerating this effect.This guess came about after reading up on the famous roman era LYCURGUS CUP in the British Museum. Although dichroic in nature it too shows similar colors attributed to gold and silver nanoparticles in the glass. A very extreme example.