Shell beads are usually flat, and very lightweight, by they are breakable! Natural shell beads include mother of pearl (pale cream), black-lip shell (creamy/pinky grey shades) and abalone (paua shell). Shell can also be dyed, either a monochrome, or patterned. It all has a lovely shimmery sheen to the surface.
Flat shell beads typically come in round, oval or square shapes, but they can also be cut into heart shapes, stars or open shapes - circles, squares etc. The coloured ones also come as nuggets and irregular shapes.
There are some stunning pendants available. Some are made of one piece of shell, others are composites of many small pieces or shell bits embedded in other materials. Wood and metal beads associate particularly well with shell. I tend not to mix shell beads with large glass or semi-precious beads; the heavier solid beads could easily chip or break the more delicate shell if not stored carefully.
Mother of pearl can also be formed into round and oval beads, though these tend to be a bit more expensive. Some lovely beads are becoming available with mother of pearl or dyed shell moulded with other materials into round or shaped beads.
I find shell beads make very good jewellery for the spring and summer months. The texture and light-reflecting qualities somehow seem to feel just right.