"the character had "bright eyes.""
I would have just glued an astronaut in his arms, but that's just me.
Oval ones, add wire legs for bugs.
Multi faceted ones for micro flying saucers, robot heads, buggy wheels, turrets. Grenades.
For fancy dungion tiles/bases.
Maybe crush orange red and yellow and mix with glue for fire/lava effects.
Or other colours for magic and water effects.
The crushed pieces may need smoothing in a container of fine sand to regain their transparency.
Use for snow and ice crystals.
Give a chicky babe mini a huge stone on her finger. If anyone asks, just say your taking Beyonce's advice.
Trade with kids for more useful fairy garden components, such as stone walls and dead fairies. Up the gems value by saying they are real.
Or just try your luck at a jewelers/pawnbrokers.
Spray them black and sneak them into Christmas stockings.