This set of four bicone beads with matching round spacer beads are very old and made of very light-weight vintage plastic. I tend towards lucite, but without doing damaging tests on it I can't be sure. The descriptions of celluloid could match too. This early plastic is colored to look like amber.
They are very old. I bought them as a vintage piece of costume jewelry 30 years ago when I was buying and selling in the eighties. It was at least thirty or forty years old then, in the Art Deco style. It was part of a whole piece of jewelry, a spectacular necklace with an extra large floral pendant, floral beads, bicones, and round spacers. However the necklace (which I used to wear) broke about 20 years ago, and some of the beads were lost.