I’ve lumped these two together because they’re both lacking color. One is translucent/transparent and the other is opaque, but their color status is the same. These beads can be glass, rock crystal, pearl, shell, bone, ivory, and a number of other materials.
Let’s start with glass. These can be perfectly clear to completely opaque white and anywhere in between. Perfectly clear glass wasn’t invented until the 14th century in Venice, when they realized they could add small amounts of manganese and antimony together to make the glass lose its color. Before that, ‘colorless’ glass was actually a very light grey, blue, green, or yellow.This is generally true worldwide, so if you see glass that looks clear from contexts that date to before the 14th century, chances are the glass is simply too thin or small to see the color in it (which is usually actually green, yellow, blue, or brown). Opaque glass is usually colorless glass with tin, arsenic, or more antimony added to make it opaque. Bone was also sometimes added to opacify glass. If opacifiers weren’t available, some manufacturers seem to have added large amounts of small bubbles to the glass to give it an opaque look.
Rock crystal is an interesting material, because it tends to mimic clear glass. You can tell if a bead is rock crystal versus glass because you won’t find bubbles in rock crystal, and any edges will appear cut instead of pressed or molded. Also, the perforation will be drilled, either from each end or only one. This will lead to the perforation looking like a cone or like two cones meeting in the middle. Glass bead perforations are never drilled. Rock crystal will also scratch glass, but glass won’t scratch it (though I don’t recommend trying to scratch artefacts). If you have a big enough bead, you can hold it up to the light and slowly rotate it, rock crystal will, at certain angles, split the light in two. Glass won’t. Careful, though, since this only works on larger pieces of quartz and will be too hard to spot if they’re smaller.
Pearl beads are fairly easy to spot, since the iridescence of the pearls is hard to replicate in another material. They will also have a drilled hole. If you’re wondering whether the pearls are real, you can tell a couple of ways. First, if you rub pearls against each other, there should be a certain amount of friction and graininess due to the layer of nacre on them. You can also rub them against the bottoms of your front teeth, but that’s not recommended with artefacts (though neither is rubbing them against each other). If the pearls are perfectly round, they are likely not natural pearls. Real pearls also have a tendency to be cool to the touch, and then warm up as you hold them. Fake pearls will sit at room temperature and won’t be cool to the touch.
Shell beads tend to be very obviously shells with holes drilled in them, or circular, thin, disk beads. Most shell beads are white, with the exception of quahog wampum beads. Whelk wampum can be white to orange, depending on which part of the shell they come from. White shell beads in the form of a disk often come from seashells (such as clams, oysters, and whelks) but can also come from eggshells, particularly ostrich. The oldest beads in the world were made between 100,000 and 135,000 years ago from the shell of a sea snail in the eastern Mediterranean. Shell beads are often brittle, and the entire bead tends to orient in a single direction across the perforation.
Bone beads can be made from any animal, including humans. If they have a light blue hue to them, it generally means the bone has been burned in some way. These can be even more fragile than shell beads, depending on how small they are. Bone is porous, and so the beads should have pock marks all over them. The perforation would be drilled and likely sanded or ground smooth. Bone beads shouldn’t be confused with ivory beads, which are coming from the teeth or tusks of an animal. Ivory can be polished a lot more than bone and gives these beads a smooth, shiny luster. Note: Ivory and the trade of ivory are illegal in most countries in 2015, and this blog does not condone those practices in any way.
White and clear beads tend to be similar to black beads in their popularity trends – highly popular in some regions and very unpopular in others. In some regions, white is associated with death, not black, leading to this similarity in patterning.
I should finish by saying that if you find a white glass bead in a context dating prior to the 14th century, that doesn’t mean your dates are wrong. Since beads are small enough, it was possible to make glass that was nearly clear (with a slight hue of yellow, green, blue, or brown) and use antimony or another mineral to turn it opaque. If the bead was small enough and the glass close enough to clear, then the bead will appear white even though it’s more of a cream color (or other light green or blue). It appears white until you compare it with, say, a piece of white printer paper. Given my technique for recording color, however, I would still classify that bead as being primarily white.