Frequently Asked Questions


About Freshwater Pearl Beads

What are the differences between saltwater and freshwater pearls?
Saltwater pearls are created by oysters that live in the ocean while freshwater pearls are created by mussels that live in freshwater lakes, rivers and streams. The pearls created by both types of mollusks are made of the same substance, nacre. While cultured saltwater pearls usually have a mother of pearl bead at their center that the animal has coated with nacre, freshwater pearls are almost always created without a bead nucleus.
What do the terms "luster," "orient," and "overtone" mean in relation to pearls?
Luster describes the way pearls seem to glow from within. It's based on the depth of reflection due to the layering of the aragonite crystal.
Overtone describes the translucent "coating" of color that some pearls have. A silver pearl may have a blue overtone or a green overtone, for example.
Orient, sometimes called iridescent orient, describes the variable play of colors across the surface of the pearl like a rainbow. While not all pearls have iridescent orient, freshwater pearls are known for their dramatic orient.
What are pearls made of?
Pearls are made of nacre, the same substance as the iridescent mother of pearl found inside the mollusk's shell. Nacre is composed of "bricks" of calcium carbonate, in the form of the crystal aragonite, cemented together by small amounts of conchiolin, a protein that acts as mortar.
What is mother of pearl?
Mother of pearl is the lustrous coating that lines the inside of an oyster or mussel shell. It's made of nacre, the same substance that pearls are made of. Only the mantle tissue of the mollusk can secrete nacre. The mantle tissue lines the shell and will coat anything that irritates the soft tissues with nacre. We sell some lovely mother of pearl beads on our Coral and Mother of Pearl Beads page.
How is the quality of a pearl determined?
The criteria that determine the quality of a pearl are based in part on the type of pearl being evaluated. In the case of freshwater pearls, these include shape, size, color, luster and surface quality. Since most freshwater pearls are sold by the strand and not as individual pearls, some of these factors, such as color and shape, are based on conformity within a particular strand.

Other factors, such as luster and surface quality, are based on each pearl's features.

In general, pearls with high luster and fewer blemishes will be more expensive than duller or more irregular pearls.
What shapes do freshwater pearls come in?
Thanks to some new nucleating techniques, freshwater pearls can be found in a nearly endless variety of shapes, but the more traditional shapes include:
  • Round - Perfectly spherical, or very nearly so. These are primarily saltwater pearls, although the Chinese have recently succeeded in creating round freshwater pearls.
  • Stick - Long and thin with many irregularities.
  • Rice - Small ovals drilled lengthwise.
  • Potato - Often lumpy, these are typically rounder than rice pearls and may be drilled either lengthwise or widthwise.
  • Nugget - Usually a little more square or pebble shaped than rice or potato pearls and almost always having a flat side.
  • Coin - Large, circular and flat, often about the size of a dime, with the hole drilled end-to-end. Coin pearls, unlike most freshwater pearls, are created using a bead nucleus. Newer coin shapes include hearts, squares, ovals and large pears and drops.
  • Keishi - Sometimes called "cornflake" pearls, these are flat and highly irregular. Keishi pearls are formed when an oyster manages to expel a bead nucleus, but continues to make a pearl.
  • Drop - Teardrop, pear or even peanut shapes, drilled either lengthwise, or widthwise at the narrowest end.
  • Button - Rondelle shaped, often with a flatter side, and drilled through the "hub" of the wheel. A "lollipop" pearl is a button pearl that has been drilled across the larger dimension of the pearl; lollipop pearls tend to be flat on the back and domed (curved) on the top.
What colors do freshwater pearls come in?
Freshwater pearls come straight from the mussel in a fairly limited palette of soft, lovely colors including cream, silvery gray, lavender, pink and peach. However, modern coloring techniques can create freshwater pearl beads in every shade of the rainbow, from fuchsia to lime green.
How are pearl bead sizes given?
Pearl bead sizes are given in millimeters.
How many pearl beads are on a 16" strand?
Pearls are typically strung on temporary strands measuring 16 inches in length. In metric measurements, this is equivalent to about 400mm. If you divide the strand length by the average length on the drilled dimension of the pearl, you will obtain an approximate idea of the number of pearls on a strand. To make this simpler, we have provided a table at the bottom of each of our pearl pages to give you a quick idea of how many pearls to expect.
How big are the holes in freshwater pearl beads?
We wish we could give you an answer to this question. Unfortunately, there can be a great deal of variation in the hole size among all gemstone beads, including pearls. Due to the somewhat delicate nature of the nacre they're made of, pearl beads generally have smaller holes than most gemstone beads, and the smaller the pearl, the tinier the hole. Keep this in mind especially when buying seed pearls (usually tiny rice or button pearls). We offer thread, bead stringing wire and needles in sizes that will work with almost all of our pearls.
How often do pearls need to be restrung?
It depends on how often they're worn and what kind of material they are strung on. For June Cleaver types who wear their pearls every day even while vacuuming the house, restringing once a year is probably a good idea. But for the rest of us, every two to three years is adequate. And if your pearl necklace spends the vast majority of its time carefully tucked away in a jewelry box, restringing every four to five years is probably okay.

Pearls strung on nylon (e.g. Polyamid) do not have to be restrung as often as those strung on silk. Pearls strung on stranded wire products (e.g. Beadalon) do not need to restrung at all.
How do I restring pearls?
Entire books have been written on stringing pearls, but we'll try to give you an overview here:

First, you should gently wash your pearls while they are still on the old string. See "How do I safely clean pearls?" (just below) for directions.

Next, you must carefully cut the pearls off the old string. To start, place your scissors on the knot between two pearls and cut through the middle of the knot. You don't want to start on either side of the first knot because the knot could slip inside a pearl and be quite difficult to remove. For the rest of the pearls, snip each knot off by placing the scissors behind each knot and in front of the pearl. Even in a fairly uniform pearl necklace, the pearls toward the back may be slightly smaller than the pearls in front, so it's a good idea to place the pearls on your bead board in the order you remove them.

Now you can restring your pearls in their original order, tying secure knots between each pearl again. If you don't already know how to knot between pearls using thread, then we recommend the book Pearl and Bead Stringing with Henrietta.
How do I safely clean pearls?
Ideally pearls should only be cleaned while still strung on the old cord or strand. After cleaning, they will need to be restrung.

Line a colander with a soft washcloth and place it in a sink with the drain closed. Put the pearls in the colander and wash them with a gentle non-detergent soap without dyes. Use a soft cloth to clean around the hole of each pearl. Rinse thoroughly and let dry overnight before removing them from the string.
How do I safely store pearls?
Because pearls are relatively soft and delicate, it's recommended that you store them either in their own box or in a separate cloth bag when keeping them with other jewelry to prevent them from being scratched by metal findings or sharp gemstones. Note: This generally applies to more expensive pearl jewelry; most people we know store their freshwater pearl jewelry right alongside their other jewelry items.
Are special tools or materials needed for pearl stringing?
Not necessarily. If you are stringing pearls like your other beads, then you can use all the usual basic beading tools (e.g., round nose pliers, chain nose pliers and a wire cutter or good quality scissors) to complete your project. Even if you are making a more traditional knotted pearl necklace, you can create the knots using only your hands. However, knotting pearls can be made a lot easier by using either an awl or a pair of beading tweezers, which allow you to more precisely control the location of the knots. Some people prefer to us a specialized knotting tool instead, especially if they are doing lots of knotting or have experienced trouble placing their knots in the desired position. We offer a variety of specialized pearl tools on our Tools for Pearl Jewelry Knotting page.
For a knotted pearl necklace, how long does the string need to be?
A good rule of thumb is 4 x length of necklace in inches + 15 inches. That assumes you are using a doubled strand of thread instead of just one. For a 16-inch necklace, that would be 79 inches (4 x 16" + 15" = 79"). When using carded thread that comes with a needle pre-attached (e.g. Griffin Polyamid) you do not need to double the thread (it has already been done for you by the manufacturer).
Can metal wire, nylon coated beading wire, or other contemporary materials be used with pearls?
Absolutely. While simple knotted pearl necklaces are classic and elegant, modern freshwater pearls are so affordable and come in such an astounding variety of colors, shapes and sizes that they can be used just like any other bead and therefore lend themselves to every beading material available. We offer both traditional pearl thread products and contemporary stringing materials for your designs.
Are there round freshwater pearls?
In the past, there were almost no perfectly round freshwater pearl beads. The closest you could find were off round. Recently, however, the Chinese have had some success in using nucleating techniques to create perfectly round freshwater pearls that rival traditional saltwater pearls. Pearl prices increase dramatically as the pearls are more round and perfect.
What is a blister pearl?
Blister pearls are simply pearls that are still attached to the shell of the mollusk. The Chinese were probably the first people to culture pearls when they implanted tiny Buddha figures between the mollusk's soft mantle tissue and its shell in the fifth century A.D. When they came back a year or two later, the shells were lined with Buddha blister pearls. We occasionaly carry blister pearls on our Pearls in Other Shapes page.
How are keishi pearls formed?
Keishi pearls are formed when an oyster rejects an implanted bead nucleus but continues to create a pearl, or when some of the implanted mantle tissue in a mussel breaks away and forms its own freeform pearl. We feature several colors and grades of keishis on our Keishi Pearls page.
What are Biwa pearls?
It depends on whom you ask. According to the Japanese, Biwa pearls are exclusively those that come from Lake Biwa, near Kyoto. Because Biwa pearls were among the first cultured freshwater pearls and were predominant in the industry until the 1970's, the term Biwa became nearly synonymous with the term freshwater pearl. As more and more freshwater pearls come from China, the Japanese may soon have their exclusive designation back.