Yes, those are really tiny sizes! Some folks use 26-gauge and smaller round wire to cage items like this, however I am going to give you a different experiment today (one my husband does with opal chips).
First, find a small, bowl-shaped item/container (maybe the top half of a domed metal button) place it on a surface that will keep it level (such as clay) and using a liquid plastic resin, pour a bit into the container. Then place the tiny cabs into the resin (top side up) until you are happy with the design. You could even fill the spaces between the cabs with seed beads, etc. Fill the remaining space with the plastic resin and let it harden completely. Now you can wrap your personally created "gemstone mosaic."
Other than that, maybe find a jeweler would trade items you can use for those tiny cabs.
Answer contributed by Dale "Cougar" Armstrong