At the Symposium speaker Greg Merkel talked about the color of glass. Part of the process of identification is through some of the specialized equipment located either at CMoG or Corning, Inc. Greg spoke of instances where they had shards of glass and could then analyze the construction of the glass from examination of the layers. However, their access to such shards is limited. Now from Rande Bly of Birmingham, Alabama he speaks of some shards he has examined with the naked eye.
This is getting interesting. I have two pieces of broken Jade here. I promise I did not break them to solve this dilemma. Both my Green Jade and my Light Blue Jade are NOT cased in any way. The broken Green Jade is made of Alabaster with the coloring agent stirred all through the mix making it Green Alabaster in a way. Rosaline or pink jade is made in the same manner.

My broken Blue Jade piece does in fact look different. It is more opaque and does look more like blue milk glass. It is very clearly homogeneous all the way across the break and totally obvious it is NOT cased in any way or have a white center. It appears to be flint white with the blue coloring stirred into the glass mix making it in a way “Flint White Blue”. It looks to be a colored with a Celeste Blue shade of color.

The Light Blue Jade Pieces from Stevens and Williams are made in the same fashion as the Steuben Green Jade and Rosaline
and is like a blue alabaster.

Now the acid cut back vase featured is obviously Alabaster. How you can tell if the vase is cased with “Flint White Blue”/ Light Blue Jade or French Blue or another Carder Transparent Colored Crystal like Celeste Blue should be as follows:

Take the vase into some bright lighting. Place the moderate light source inside the vase so it shines through the Alabaster first and look toward the light source through the blue from the outside of the vase. If it is cased with one of Carders transparent colored crystals you will be able to clearly see the clambroth matrix of the alabaster showing clearly through the extremely transparent French or Celeste Blue it is cased with. It will look just like Rosaline only blue in color. It will appear to be blue alabaster.

If it is cased with Flint White Blue / Blue Jade you will not be able to see any of the clambroth matrix of the Alabaster showing through the blue. Flint White is considered to be an opaque color and you should not be able to see the Alabaster through it. Although, even as with Steuben’s Mirror Black all of his opaque colors do have an internal color if held to a bright enough light source(such as the direct ball of the sun).

Experiment to get the right light intensity and this will solve the question of the vase being cased in Blue Jade or French Blue. One last comparison will have to be made to be sure it is not Celeste Blue and by placing both a piece of French Blue and Celeste Blue side by side with the vase you will be able to make this differentiation.

PS If the vase is in fact purple in any slightest way rather than blue then it will be Heliotrope. Then we can discuss whether Heliotrope is a faint light purple alabaster jade or a Carder Transparent Colored Crystal. Tee Hee. Working with photos is a real challenge.

Please try the test and you will be able to tell what the blue casing is.