Just what kinds of beads were being used in trade by Captain Cook's ships and Russian traders as well is found in the records of events far north of Nootka Sound. In May of 1778 in the vicinity of Prince William Sound, Alaska, Cook's journal records that a native, "...cloathed in a dress made of Sea beaver skin and on his head such a Cap as is worn by the people of King George's Sound, Ornamented with sky blue glass beads about the size of a large pea, these he seemed to set ten times more Value upon than our white glass beads which they probably thought was only crystal which they have among them. They, however, essteemed [sic] beads of all sorts and gave whatever they had in exchange for them, even their fine Sea beaver skins.'(Beaglehole 1967: III, 346). Thus Captain Cook's ships are carrying white glass beads of unstated size and shape, and the Russians who had a monopoly on the fur trade of the Northwest Coast were using sky blue glass about the size of a large pea and presumably round. There is some additional information about these beads from the pen of Captain James King who was responsible for the third volume of Cooks' third voyage. He wrote of the natives of Prince William Sound (Beaglehole 1967: III, 1418) as follows: '... but the most certain proofs of their having a frequent supply of articles belonging to civiliz'd Nations are their blue beads; these of which they set a very great Value, have not the good shape of English beads but are manufactur'd by some Nation rudder in this art than ourselves, they are a bead about the size of a large currant berry, & intended to be (but are not) round'.
This and more found in Archaeological essays in honor of Irving B. Rouse, Google Books.