Is the color opaline just silver fumed glass? What makes it different than a silver fumed rod?

This is a trade secret to the manufacturer.  While it does seem to look like a great fumed piece of glass, we feel it is not fully the same;  There is some kind of another mineral in it that gives it a sheen.  Also, it does not fully work like clear fumed glass.

We find it a touchy glass and can crack easily.