Marshall Ketchum responds to Rande Bly on what is light jade blue:
Alan

Rande’s examples of Light Blue Jade shown in the color plates of the Gardner book are interesting but he is in error. These two examples do not show the Flint White in the sandwich and this is often the case even though if we could handle the pieces we would find they are cased. When the piece is being made it is often the case that as the glass is worked the blue is rolled over the white at the edge and the Flint White cannot be easily seen. Sometimes the only place the Flint White can be seen is in the pontil where it is ground through the blue layer into the White. Sometimes the pontil isn’t ground deeply enough and the Flint White doesn’t even show there. One can be sure that the casing is there because without the Flint White layer what we call Light Blue Jade would look much different than it does. I have heard of only one example that may exist where Light Blue Jade may be a solid color and is not cased. There is reference to such a piece on the Philpot record or the booklet that accompanies it. This reference is 45 years old and one wonders if the mention of this occurrence was really correct.