| Original Message: Faience vs. Powderglass |
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Hello Uwe, The thing is, both faience and powderglass beads—in terms of their manufacture—can have a lot in common. In both manufactures, the maker can begin with crushed material, that is often made into a paste (with water and/or another binder), and sculpted or used to charge a mold. Faience is sintered—meaning it's heated enough so that glass forms around each granule of quartz, and this glass/glaze is what holds everything together. A glaze also usually forms on the exterior of faience beads (and artifacts)—though it can also be placed there intentionally as an operation. And, over a long period, this external glaze can tend to disappear (depending on conditions). But most faience was shiny and glassy-looking when it was new/ Powderglass beads likewise sinter, rather than fusing to a homogenous mass. So they can look very much like faience, and they can seem different from conventional glass. The difference is, faience beads are only colored on the exterior, and remain white, off-white (or whatever) inside—whereas the glass beads are colored throughout their masses. (However, there is a faience-like material, usually called "Egyptian Blue" that is colored a bright distinctive blue throughout its mass. It is said that Egyptian Blue—which came from other regions too, by the way—was not ever self-glazing. ) If you have an opportunity to view the end of a bead, you might get an indication of its structure. Your bead appears to be glass all the way through, and so is not faience. If you could see the Egyptian beads on the end, there would probably be some indication of the white base color. Also, faience was most likely NOT "invented in Egypt." Like glass technology, it was probably invented in Mesopotamia, and taken to Egypt. Even in the professional world, people make mistakes when trying to identify materials. LOTS of people still call faience a "ceramic" (a practice I discourage, because it is not composed from clay). Many times, glass beads are identified as clay/ceramic (as happened with the beads from Ban Chiang some years ago--until I told them differently at the U of PA Museum); and many people are confused about faience and glass. MANY Chinese scholars and collectors fervently believe that Han Dynasty glass beads "are faience"—because the glass can be very decayed. However, the winding striations are usually easy to see—and faience is NOT wound to make a bead. But even European and American scholars cannot identify glass (when it is decayed) and other materials properly, and make similar mistakes. Thus, we get names like "frit," "paste," and "glassy faience" for what are probably something else..... I hope this helps. Jamey All rights reserved by Bead Collector Network and its users |
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