Some gemstones that are used in the beading world are "reassembled". The reason usually is that the gemstone is in short supply, or that it is too unstable (crumbly) to make a well shaped bead with a nice glossy polish.

Typical examples are Chrysocolla and Azurite Malachite. In these instance, the manufacturer buys whatever chips and bits of the stone that they can. They break it into small, somewhat uniformly size pieces, then reassemble it into usable sized blocks using a special type of adhesive and a method that sometimes also used heat and pressure to achieve a dense material. The beads are then cut from the reassembled material. In most cases, the resulting stone is much stronger and much more stable than the original gemstone.