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About Czech Glass Pearls Before I tell you about glass pearls, let me tell you first how real pearls are made (you may already know this). When a foreign object, such as a pebble, gets into an oyster or other mollusk, the oyster will secret a hard, lustrous substance around the object to protect itself. This substance is called "nacre", and it is the same substance that the oyster secrets on the inside of the shell, which results in "mother of pearl". As time passes, the oyster continues to secret nacre around the object, and the pearl continues to grow. By the time the oyster dies or the pearl is harvested, the pearl may consist mostly of nacre. Thus, a natural pearl has a very thick nacre and will be very hard and durable. In the case of cultured pearls, the manufacturer will insert an object (usually made from shell) into the flesh of the oyster, where the oyster is sure to be irritated by it. The shape of the object will determine the shape of the resulting pearl. The oyster then secretes nacre around the object. However, the object won't be left in the pearl for very long, so the resulting pearl won't have a very thick layer of nacre, certainly much less than a natural pearl has. In other words, a cultured pearl may consist mostly of the original object, whereas a natural pearl may consist mostly of nacre. In the case of glass pearls, the manufacturer will string white glass beads on a heavy string, and then the "nacre" (which is actually a special glossy polymer-based paint) will be sprayed onto the beads. Since the "nacre" of glass pearls is really just a coat of paint, it is very thin (thinner than the nacre of a cultured pearl). It is fair to assume that the paint is formulated to adhere to the glass bead, but I know from experience that it can be pealed off. Common Defects The white beads that are sprayed with synthetic nacre are spaced about 1/4" apart on the string. Sometimes two beads will be touching, and in that case the nacre will fuse the beads together and they won't be usable. After the nacre dries, the manufacturer will shove the beads together in the center of the string. When they do that, the nacre on some beads may catch on the string and get pulled off the ends of the beads. Thus, on every strand of glass pearls, there will be a few that are missing nacre around the holes. Finally, the synthetic nacre sometimes has surface defects. I have seen pits, bubbles and bumps, though they aren't common. Cube-shaped glass pearls seem to have more blemishes than round pearls. One other defect: Sometimes there is a little excess coating over one or both holes of a glass pearl, and it forms what looks like a hang nail sticking out from the hole. The best way to remove that is with cuticle nippers. In short, from a strand of 75 glass pearls, you should get 70 to 73 good ones. Once in a while you'll get lucky and they'll all be good. Please note that I have no idea how Swarovski pearls are made, but I assume they use a similar process of spraying glass beads (given the price, I assume that the nacre is thicker than on Czech pearls). Swarovski pearls are very hard and are more likely to be defect-free than Czech pearls. Other Synthetically Coated Beads Other synthetically coated beads may or may not have similar defects to the ones that glass pearls have. Some synthetically coated beads will be fire-polished (heat-treated) to harden the coating. On fire-polished beads, the coating may be softer around the hole, apparently because the heat didn't reach between the beads very well. I believe that the Czech manufactures use more than one kind of synthetic coating (i.e., more than one formulation). I say that because they have different "feels" – some feel like plastic and some feel hard, like glass. |