The materials used to make the bead affect where it can be used. This is particularly evident with natural mineral beads. Certain minerals do not stand up well to rough treatment or actions such as washing.
Fluorite or opal can easily chip, crack or scratch. Other minerals are frequently dyed different colors so that they resemble other more expensive or less easily obtainable gemstone minerals.
Howlite is one such mineral. Naturally white in color, it is often dyed pink to resemble rhodochrosite or blue to mimic turquoise. When exposed to water, however, the dye can run and ruin a piece of lacework. Test a bead by placing it in a glass or water overnight. If the bead is the same color and hardness then it should be safe to use in your tatting. If, however, the bead is faded or lost its color or is starting to disintegrate, the bead is not suitable for your lace. A mineral that is sensitive to water will also be affected by the humidity in the air. The moisture in the air can make a dyed bead bleed color onto your tatted lace.
Amber was traditionally used for beads, but it is clear enough to allow the tatting thread to show through the bead. This fact may not produce the effect desired.
Whatever material is used to make the beads, breakage or flaking is major consideration. Since the beads are tatted into the design and not sewn onto the work after the lace is completed, the replacement of a bead means that part of the work will have to be dismantled and re-tatted in order to restore it.
Be careful of imitation pearl beads that have a coating sprayed on them to give a pearl effect. Over time this coating can darken, chip, or flake showing a milky white plastic underneath. A couple of peeling beads will detract from the overall appearance. Try to find "pearly" beads that have the pearl effect in the plastic or in the glass and not added as a coating. Except for certain earring patterns I avoid plastic totally. There are beautiful glass, crystal, stone, gemstone, porcelain, leather, wood beads available.
The richer looking the bead, the better it will enhance your lace. There is also something satisfying about using materials that were employed by traditional lacemakers. Rock shops that cater to true rockhounds (rather than rock shops that cater to tourists) often have a rich collection of drilled gemstone and true mineral beads that are sized and temporarily strung.
* Special thanks go to my brother, Gary, for his time and effort in contributing to the information on suitable bead materials. I especially appreciate his insights and extensive knowledge on various rock and gem materials and appreciate his patience when faced with my many questions on how these materials might affect the work of today's tatters and lacemakers.